Answer:
Therefore
15.
16.
17.
Step-by-step explanation:
15.
Using the Identity (a + b)(a - b) = (a² - b²) we get
Consider here a = 5c and b = 3 then we will have
.....as required
16.
Here Factorize 8 such that sum up to be 9
∴ 8 × 1 = 8 and 8 + 1 =9
... as required
17.
Here Factorize 21 such that sum up to be -10
∴ -3 × -7 = + 21 and -3 - 7 = - 10
........as required
Therefore
15.
16.
17.