6r+ 7 = 13 + 7r
r = -6
13 − 4x= 1 − x
x = 4
−7x− 3x+ 2 = −8x− 8
x = 5
−14 + 6b+ 7 − 2b= 1 + 5b
b = -8
−6n− 20 = −2n+ 4(1 − 3n)
n = 3
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