If A and B are in the ratio 4 : 5 and the difference of their squares is 81, what is the value of A?
Let A = $$4x$$ and B = $$5x$$
Difference in their squares = $$(5x)^{2} - (4x)^{2}$$ = 81
=> 25$$x^{2}$$ - 16$$x^{2}$$ = 81
=> $$x^{2}$$ = $$\frac{81}{9}$$
=> $$x$$ = 3
value of A = 4*3 = 12
Create a FREE account and get:
