Question

Leeza did this to solve an equation. Did she makes an error 4x=7+3(2x-5) 4x=7+6x-5

Answer 1

Yes, there was a mistake in applying the distributive property. If you have to perform

$3(2x-5)$

you have to multiply both terms in the parenthesis by 3, not just the first one.

So, the correct expansion would be

$3(2x-5) = 3\cdot 2x - 3 \cdot (-5) = 6x-15$

Answer 2

she has not distributed - 5 by 3 = - 15

4x = 7 + 3(2x - 5) ( distribute by 3 )

4x = 7 + 6x - 15 ( subtract 6x from both sides )

4x - 6x = 7 - 15

- 2x = - 8 ( divide both sides by - 2 )

x = $\frac{- 8}{- 2}$ = 4