By Sara Easum A quiz over simple algebraic expressions Click on the arrow to start the quiz!

 Find x and y using the following 2 equations  y=2x+4  x=y-8  Choose the correct answer A. y=5, x=12 y=5, x=12 B. y=6, x=8 y=6, x=8 C. y=12, x=4 y=12, x=4 D. y=4, x=12 y=4, x=12

Hint: plug the x= equation in for x in the y= equation Click on the arrow to go back to the question and try again!

A: Plug y-8 in for x in the y=2x+4 equation to get y=2(y-8)+4. Solve for y. y=2y-16+4; y=2y-12; y- 2y=-12; -y=-12; y=12. Then plug 12 in for y in x=y- 8; x=12-8; x=4 Click on the arrow to go to the next question.

 Find r and q using the following 2 equations.  r=3q+1  q=5r+9  Choose the correct answer A. r=-2, q=-1 r=-2, q=-1 B. r=2, q=1 r=2, q=1 C. r=-1, q=-2 r=-1, q=-2 D. r=1, q=2 r=1, q=2

Hint: Plug q=in for q in the r= equation in order to get r. Click on the arrow to go back and try again

A: Plug q=5r+9 in for q in r=3q+1 to get r=3(5r+9)+1; r=15r+27+1; r-15r=28; -14r=28; r=-2. Now plug r=-2 in for r in q=5r+9 to find q. q=5(- 2)+9; q=-10+9; q=-1 Click on the arrow to go to the next question

 Find a and b using the following two equations  a= 9b+7  a=3b+1  Choose the correct answer A. a=3, b=7 a=3, b=7 B. a=-2, b=-1 a=-2, b=-1 C. a=5, b=3 a=5, b=3 D. a=-6, b=-1 a=-6, b=-1

Hint: Solve on of the a= equations for b and plug that in for b in the other a= equation and solve for a, then plug your a in for a in the equation that you solved for b. Now solve for b. Click on the arrow to go back to the question and try again

A: if you solve a=3b+1 for b and get b=(a-1)/3 then you can plug that in for b in a=9b+7 to get a=9((a- 1)/3) +5. then solve for a. a=3(a-1)+5; a=3a-3+7; - 2a=4; a=-2. Then plug in a=-2 in for a in b=(a-1)/3. b=(-2-1)/3; b=-3/3; b=-1 Click on the arrow to go to the next question

 Find x, y, and z using the following 3 equations  x=2y+8  y=9x+4z+12  z=10x+2y+4  Choose the correct answer A. x=2, y=4, z=-4 x=2, y=4, z=-4 B. x=0, y=6, z=5 x=0, y=6, z=5 C. x=-2, y=-1, z=7 x=-2, y=-1, z=7 D. x=0, y=-4, z=-4 x=0, y=-4, z=-4

Hint: Plug equation z in for z in equation y and solve for y. Once you get an equation for y plug that into the x equation to get the x value. Once you have the x value plug that into the new y equation you got to get y. Then plug both those values into the z equation to get the z value. Click on the arrow to go back to the question and try again

A:Plug the z= equation into the y= equation to get y= 9x+4(10x+2y+4)+12; y=9x+40x+8y+16+12; y=49x+28+8y; y- 8y=49x+28; -7y=49x+28; y=-7x-4. Now plug the new y= equation into the x= equation to get the value of x. x=2(-7x- 4)+8; x=-14x-8+8; x+14x=0; 15x=0; x=0. Now plug the x value into the second y= equation. y=-7(0)-4; y=-4. Now plug the x value and the y value into the z equation to get the z value. z=10(0)+2(-4)+4; z=0+(-8)+4; z=4-8; z=-4. Click on the arrow to go to the next question

 Find p, q, and r using the following 3 equations  p=2q-3  q=4p+2r+1  2r=q+4p+7  Choose the correct answer A. p=3, q=2, r=-6 p=3, q=2, r=-6 B. p=-1, q=1, r=2 p=-1, q=1, r=2 C. p=4, q=-2, r=1 p=4, q=-2, r=1 D. p=2, q=-1, r=1 p=2, q=-1, r=1

Hint: Plug the q equation into the 2r= equation and solve. When you get a value plug that value in for the corresponding letter and solve again until you get all three values. Click on the arrow to go back to the question and try again

A: Plug q=4p+2r+1 into 2r=q+4p+7 to get 2r=(4p+2r+1)+4p+7 and solve. 2r=4p+2r+1+4p+7; 2r=2r+8p+8; 0=8p+8; -8p=8; p=-1. Now plug p=-1 into the p=2q-3 equation and solve for q. -1=2q-3; -1+3=2q; 2=2q; q=1. Now plug both values into 2r=q+4p+7; 2r=1+4(-1)+7; 2r=8-4; 2r=4; r=2. Click on the arrow to go to the next question

 Find a, b, c, and d using the following 4 equations  a=2b-1  b=a+2c+1  c=2a-2b+d+3  d=a+3b+c+4  Choose the correct answer A. a=-1/3, b=1/3, c=-1/6, d=9/2 a=-1/3, b=1/3, c=-1/6, d=9/2 B. a=-1/2, b=2, c=2/3, d=4/5 a=-1/2, b=2, c=2/3, d=4/5 C. a=3, b=4, c=-1, d=-3 a=3, b=4, c=-1, d=-3 D. a=3/7, b=4, c=4/5, d=5/6 a=3/7, b=4, c=4/5, d=5/6

Hint: Plug the smallest equation into the next smallest equation and solve for one letter. Repeat until 3 of the 4 equations are all equal to an equation with only one letter in it. Then plug all the manipulated equations into the unchanged equation to get your first value. Then plug that value into each one of the manipulated equations to get all the values. Click on the arrow to go back to the question and try again

A: Plug equation b into equation a to get a=2(a+2c+1)-1; a=2a+4c+2-1; a-2a=4c+1; -a=4c+1; a=-4c-1. Now plug the new equation into equation b. b=(-4c-1)+2c+1; b=-4c+2c- 1+1; b=-2c. Now plug both of the manipulated equations into equation d. d=(-4c-1)+3(-2c)+c+4; d=-4c-1-6c+c +4; d=3-9c. Now plug all of the manipulated equations into c and solve for c. c=2(-4c-1)-2(-2c)+(-9c)+4; c=-8c-2+4c-9c+4; c=-17c+4c-2+4;c= 13c+2; c-13c=2; -12c=2; c=-1/6. Now plug c into each manipulated equation to get all the other values. a=-4(-1/6)-1; a=2/3-3/3; a=-1/3. b=-2(-1/6); b=1/3. d=3-9(-1/6); d=18/6+9/6; d=9/2 Click here to end the quiz