Question

Find the values of the following expressions: 16x²+25y²+40xy, when x = 1/4 y = 1/5​

Answer 1

16x²+25y²+40xy ------(i)

x = 1/4 y = 1/5

putting value of x & y in eq (i)

16×($\frac{1}{4}$)²+25×($\frac{1}{5}$)²+40×$\frac{1}{4}$×$\frac{1}{5}$

= (16×$\frac{1}{16}$)+(25×$\frac{1}{25}$)+(40×$\frac{1}{4}$×$\frac{1}{5}$)

=1+1+2

= 4