Question

please don't ignore my question.. i have my exam tommorow.. please help me solve these two questions..​

Answer 1

Step-by-step explanation:

In first question, you should square the 81 too

So ans will 6561-91/(-2)

So xy = -3235

In second , divide eqn by 5

So x²-y²= 100

So (x+y)(x-y) = 100 {(a+b)(a-b) = a²-b²}

Here , given that both are same , so (x+y)= 10 , and (x-y) = 10 , because 10×10 = 100