Think about… How is an equation like a balance scale? In x + 1 = 3, what is the value of x? How do you know?
Variables on Both Sides of an Equation Mrs. Spanier Algebra 1
Solve: 7x + 19 = -2x + 55 Combine like terms Add 2x to both sides
Solve: 9x + 19 = 55 Subtract 19 on both sides
Solve: 9x = 36 Divide by 9 on both sides x = 4
Check Your Work... ...Are Both Sides Equal?
Remember… Same Sides Simplify Opposite Sides Do the Opposite
Solve: 2x + 3(4x – 3) = 8 – 3x 14x – 9 = 8 – 3x Distribute first Combine like terms 14x – 9 = 8 – 3x
Solve: 14x – 9 = 8 – 3x Solve as before… 17x – 9 = 8 17x = 17 x = 1
You try … Now try the remaining 2 examples on your G.O. with a partner.
Solve: 16 – 3x = 11 + x 16 = 11 + 4x 5 = 4x 1.25 = x
Solve: -4 – 2 + 3x = 6x – 3 + 5 -6 + 3x = 6x + 2 -6 = 3x + 2 -8 = 3x
You Try: 7 + 3h = -1 – 5h h = -1 5t – 4 = 4t – 4 t = 0
You Try: -5r – 1 = 2(r + 24) r = -7
You Try: 0.7w + 16 = 27.28 – 4w w = 2.4
The End