Question

25x²-70xy+49, when x=15and y=5​

Answer 1

Answer:

1600

Step-by-step explanation:

25x square - 70xy + 49

= (5x) square + (7) square - 2 × 5x × 7y

=(5x - 7y) square

substituting values of x=15 and y=5,

we get the answer as

{(5×15) - (7×5)} square

that is, (75 -35) square= 40 square

hence,our answer is 1600