12x15=18(3x+4)
180=54x+72
-72 -72
108=54x
/54 /54
2=x
X=2 the other person is a d0uche for answering like that so I answered instead of them
for a normal triangle its (bh)/2 but this is a right triangle so you multiply the two perpendicular sides and divide it by 2
Estimation for addition: 86 rounds up to 90 and 17 rounds up to 20 so:
90 + 20 = 110
Estimation for subtraction is the same thing but with subtraction
90 - 20 = 70
Now for the exact answers:
86 + 17 = 103
86 - 17 = 69
Your answers are 110, 70, 103, and 69.
