Answer:
A) x=39
Step-by-step explanation:
117 = 3x
117 divided by 3 = 39
3x = 117
3(39) = 117
117 = 117
A) x = 39
 
        
             
        
        
        
Since the area of a triangle is in the form 
area=0.5(base)(height)
height=base+7
let base=x
area=0.5(x)(7+x)
30=3.5x+0.5x^2
multiply the equation by 2
60=7x+x^2
subtract 60 from both sides 
x^2+7x-60=0
(x-5)(x+12)=0
thus  x=5 or x=-12 since we are only considering positive answers
x=-12 is rejected 
so base=5 and height=5+7=12
        
             
        
        
        
Y intercept = when x = 0
Plug in x = 0
0 + 3y = 6
3y = 6, y = 2
Solution: a, (0,2)