I believe the opposite of a number would be the negative of that number. Haven't seen it worded like that before though. Five less is minus 5. Three times the sum is 3(x+(-7)). Is would be equals.
x= a number
Equation: -x - 5 = 3(x + (-7))
If you solve for x: -x - 5 = 3(x + (-7)) -x-5=3(x-7) -x-5= (3*x) + (3*-7) -x-5= 3x-21 Add -x to both sides -5= 4x-21 Add 21 to both sides 16= 4x Divide both sides by 4 4= x
