Choose the two number sentences that are true. A. 5+7= 11+2
B. 3 + 3 = 20 - 9
C. 5+9 = 19 - 4
D. 12 +7 = 5 + 14
E18 - 6 = 15 - 1

D

because 12+7=19

5+14=19

it's equivalent, so we can say that its equal.

let's call the denominator x and the numerador is 18 less then denominator, x - 18.

multiply

2.x = 5.(x - 18)

2x = 5x - 90

90 = 5x - 2x

90 = 3x

x = 90/3

x = 30

so: