7(j)=91
j=13
I wasn't sure whether you wanted this to be solved or just to be put into an equation.
Area of Triangle: bh1/2[base x height x 1/2(divide by 2)]
Plug in- 10 x 7 x 1/2
70 x 1/2
35
No, the sum of the lengths of any two sides must be greater than the length of the third side
10(4x+3)-9x
40x+30-9x
31x+30
I think the answer is A