15y^2-15y+2y+7-2y^2+4

13 y^2 - 13 y + 11

Step-by-step explanation:

Simplify the following:

15 y^2 - 2 y^2 + 2 y - 15 y + 4 + 7

Grouping like terms, 15 y^2 - 2 y^2 + 2 y - 15 y + 4 + 7 = (15 y^2 - 2 y^2) + (-15 y + 2 y) + (7 + 4):

(15 y^2 - 2 y^2) + (-15 y + 2 y) + (7 + 4)

15 y^2 - 2 y^2 = 13 y^2:

13 y^2 + (-15 y + 2 y) + (7 + 4)

2 y - 15 y = -13 y:

13 y^2 + -13 y + (7 + 4)

7 + 4 = 11:

13 y^2 - 13 y + 11

option (b) is correct

step-by-step explanation:

to find the solution of this system, we need to convert it into reduced row-echelon form. we have,

after applying row operations r2 -> r2/2 and r3 -> r3/3, we get,