x + 12 = -24 + 21
x + 12 = -3
x + 12 = -3 - 12
x = -15
\(x+12=\left(-24\right)+21.\)
\(x+12=-3.\)
\(x=\left(-3\right)-12.\)
\(x=\left(-3\right)+\left(-12\right).\)
\(x=-15.\)
` x + 12 = -24 + 21`
` x + 12 = -3`
` x = -3 - 12`
`x = -15`
x + 12= -24 + 21
x + 12= -3
x= -3 -12
x= -15