Explanation:
Hay Maths Citizen!
To solve for x we have to add the two values of the opp side.
42 + 28 = 70
Secondly, Divide 42 by 70
42 ÷ 70 = 0.6
Thirdly, Solve where 0.6x = 90
0.6x = 90
x = 90/0.6 = 150
Now the total length of the hyp is 150.
To get 4x just substract 150 from 90 and the solve for 4x
-> 150 - 90 = 60
4x = 60
x = 60 / 4 = 15
[ Interpretation of the triangle image inserted - A slanted triangle with a line across half of the triangle. the hyp is splited into two as a result of the line cut across in the half the top in the hyp is 90 and the down is 4x while on the other side known is the opp side is splited into two values as a result of the line in the center top and down the top is 42 and the down value is 28 ]