Question

9.If a - b = 7 and a + b = 9, then a² - b² = ​

Answer 1

Answer:

63

Step-by-step explanation:

a-b = 7

a = 7 + b -----> eq.1

applying eq.1 at a + b = 9

7 + b + b = 9

7 + 2b = 9

2b = 9 - 7

2b = 2

b = 2/2

b = 1

now let's apply the value of b to find a at a + b = 9

a + 1 = 9

a = 9 - 1

a = 8

the value of a² - b² =

8² - 1² = 64 - 1 = 63