Well area of a triangle is

so,

The answer is 8
Answer:
m=1
Step-by-step explanation:
12m+5=17
-5 -5
12m=12
m=1
The group of those shapes are parallelograms
Answer:
x=4 y=0
Step-by-step explanation:
3x+5y=12
-(x-3y=4)
3x+5y=12
3(-x+3y=-4)
3x+5y=12
-3x+9y=-12
14y=0
y=0
Then, substitute the y into the equation to find x
x-3(0)=4
x=4