Question

3 - y2 + 7 for y = 5

Answer 1

Ответ:

{3(2x-y)-5(x+y)=-7

{2(x+4y)-5y=5

6x - 3y -5x - 5y =-7

2x + 8y - 5y = 5

x -8y = -7

2x + 3y = 5

x = -7 + 8y

2(-7 + 8y) + 3y = 5

-14 + 16y + 3y = 5

19y = 5 + 14

19y = 19

y = 1

x = -7 + 8 * (1)

x = 1

Ответ (1; 1)

Answer 2

It looks like you're asking to substitute the value of y into the expression 3 - y^2 + 7 when y is equal to 5. Here's how you would do it:

Expression: 3 - y^2 + 7 Value of y: 5

Substitute the value of y into the expression:

3 - (5^2) + 7

Calculate the value of the expression:

3 - 25 + 7 = -15

So, when y is equal to 5, the expression 3 - y^2 + 7 evaluates to -15.