Question

cuanto es 3x+4.2=158.7

Answer 1

3X= 158.7 - 4.2
3X= 154.5
X=151.5/3
X=51.5

Answer 2

$3x + 4.2 = 158.7 \\ 3x = 158.7 - 4.2 \\ 3x = 154.5 \\ x = 154.5 \div 3 \\ x = 51.5$
y la verificacion seria correcta

3×51.5+4.2=158.7
154.5+4.2=158.7
158.7=158.7