You need to get x by itself by performing the same operations on both sides of the equation
7x - 8 = 3x + 12
add 8 to BOTH sides
7x = 3x + 20
subtract 3x from BOTH sides
4x = 20
divide BOTH sides by 4
x = 5
12 + 5 equals...
a= -0.8
-0.5
If n + 7 = 12, then n = 12 - 7
-12=m+4 -16=m
-3
7x = 3x - 12 4x=-12 x=-3
X=6
X = 12
A + 9 = 21 A = 21 - 9 A = 12
5 plus 25 equals 60. Need to solve for 5 plus 25 equals ?: 2 plus 10 equals 24 is equivalent to 2 × (1 plus 5) equals 2 × (12); and 3 plus 15 equals 36 is equivalent to 3 ×(1 plus 5) equals 3 × (12); thus 5 plus 25 equals ? is equivalent to 5 × (1 plus 5) equals 5 × (12); thus ? = 5 × 12 = 60.
x = 4 and y = 0