Question

Simplify (s + 7t) (75 - t) for
s = 3 and t = -2​

Answer 1

(s + 7t) (75 - t)

(3+7*-2)(75-(-2))

(3-14)(75+2)

-11*77

-847

Answer 2

Answer:

Given,

• s = 3

• t = - 2

To Find :-

Value of :- (s + 7t) (75 - t).

Solution :-

(s + 7t) (75 - t)

Substituting Value if 's' and 't'

= ( 3 + 7(-2)) (75 - (-2))

= (3 - 14) (75 + 4)

= ( -11) ( 79)

-11 $\sf\times$ 79

= -869

Useful Algebraic Identities :-

1) (x + a)(x + b) = x² + (a + b)x + ab

2) (x - a)(x - b) = x² - (a + b)x + ab

3) (a + b)(a - b) = a² - b²

4) (a + b)² = a² + b² + 2ab

5) (a - b)² = a² + b² - 2ab