Add the three angles and set them to 180
4x-13+15+x+18=180
5x+20=180
5x=160
x=32
Then plug in to get A and C
A=4*32-13
A=115
C=32+18
C=50
Answer:
The correct answer is 18
the correct expression is 
Step-by-step explanation:
let the number be n
therefore if he is required to multiply n by 4 and added to 6 we have

given that he did otherwise by adding 6 to n and multiply by 4 we have

Firstly we need to solve for n in equation 2

Dividing both sides by 4 we have

In order to solve for the correct answer let us input n=3 in equation 1 we have

Answer:
According to SSS (side, side, side)
Step-by-step explanation:
Hope it helps...
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I believe the product of the equation is 439.43
Answer:
the answer are x=4 and y=-3. answer C