# Math

posted by David

5x - 3 = 7x + 11
x=-4

3w -4 = w+8
w =6

1. Ms. Sue

Let's substitute.

(5 * -4) - 3 = (7 * -4) + 11
-20 - 3 = -28 + 11
-23 = - 17
Nope. That doesn't work.

(3 * 6) - 4 = 6 + 8
18 - 4 = 14
14 = 14
Yep. This one works!

2. Reiny

5x - 3 = 7x + 11
x=-4 <------------ No

5x-7x = 11+3
-2x = 14
x = -7

3w -4 = w+8
w =6 < --------- Yes

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