Answer:
1). (3² - 4²) = 29
2). 5a - 7b + b² = -15
Step-by-step explanation:
Points to remember
1) (a² - b²) = (a + b) (a - b)
Solve 22 - (3² - 4²)
To find (3² - 4²)
(3² - 4²) can be written as,
(3² - 4²) = (3 + 4 ) (3 - 4) = 7 * -1 = -7
22 - (3² - 4²) = 22 - (-7) = 22 + 7 = 29
22 - (3² - 4²) = 29
To solve 5a - 7b + b²for a = -1 and b= 5
Substitute the value of a and b in given expression we get,
5a - 7b + b² = (5 * -1) - (7 * 5) + 5²
= -5 - 35 + 25 = -15
Therefore 5a - 7b + b² = -15
