Chapter 4 Section 4.B Solve equations in the form ax^2+bx+c In this assignment, you will be able to... 1.Solve equations in the form ax^2+bx+c 2. Find the zeros of a quadratic. 3. Solving quadratic models.
1.)16x^2-1=0 Solve the equation.
16x^2-1=0Original equation. Answer: (4x+1)(4x-1)=0 4x+1=0 or 4x-1=0 4x=-1 or 4x=1 x=-1/4 or x=1/4 Factor equation. Set factors equal to zero. Subtract. Divide. x=-1/4 or x=1/4
2.)11q^2-22=0 Solve the equation.
Answer:x=-2 or x=2
3.)14s^2-21s=0 Solve the equation.
Original equation. Answer: 7s=0 or 2s-3=0 2s=3 s=0 or s=3/2 Factor monomial. Set factors equal to zero. Add. Divide. 14s^2-21s=0 7s(2s-3)=0 s=0 or s=3/2
4.)45n^2+10n=0 Solve the equation.
Answer:x=0 or x=-2/9
5.)4x^2-20x+25=0 Solve the equation.
Original equation. Answer: 2x-5=0 2x=5 x=5/2 Factor equation. Set factor equal to zero. Add. Divide. x=5/2 4x^2-20x+25=0 (2x-5)(2x-5)=0
6.)4p^2+12p+9=0 Solve the equation.
Answer:p=-3/2
7.)15x^2+7x-2=0 Solve the equation.
Original equation. Answer: 3x+2=0 or 5x-1=0 3x=-2 or 5x=1 x=-2/3 or x=1/5 Factor equation. Set factor equal to zero. Subtract,Add. Divide. (x+2)(x-1)=0 15x^2+7x-2=0 x^2+7x-30 (x+10)(x-3)=0__ 15 Divide factors by 15. Reduce. 5 __ 3 x=-2/3 or x=1/5
8.)6r^2-7r-5=0 Solve the equation.
Answer:r=-1/2 or r=5/3
9.)36z^2+96z+15=0 Solve the equation.
Answer:x=-5/2 or x=-1/6
Find the zeros of the function by rewriting it in intercept form. 10.)y=4x^2-19x-5
Answer:x=-1/4 or x=5 Original function.y=4x^2-19x-5 x^2-19x-20 Factor. Set equal to zero. Multiply 4*(-5) (x+1)(x-20)=0 Divide factors by ___ Reduce. Bring 4 out front.(4x+1)(x-5)=0 Set factors equal to zero. Solve for x. 4x+1=0 or x-5=0 4x=-1 or x=5 x=-1/4 or x=5
Find the zeros of the function by rewriting it in intercept form. 11.)g(x)=3x^2-8x+5
Answer:x=5/3 or x=1
Find the zeros of the function by rewriting it in intercept form. 12.)y=5x^2-27x-18
Answer:x=-3/5 or x=6
13.) A surfboard shop sells 45 surf boards per month when it charges $500 per surfboard. For each $20 decrease in price, the store sells 5 more surfboards per month. How much should the shop charge per surfboard in order to maximize monthly revenue?
Answer:$340
14.) Solve the equation 24x^2+8x+2=5-6x. Describe each step.