what is the solution of the system?

use the substitution method.

{y+7=3x
6x−2y=12

(a.) (14, 12)
(b.) (12, 14)
(c.) there is no solution.
(d.) there are an infinite number of solutions.

Simplify 15(x - 4)(x -1)-3(x + 4)(x - 1) with steps

Which of the following statements is true? a. the irrational number system is not closed under multiplication, because the product of two irrational numbers is always a rational number. b. the irrational number system is not closed under multiplication, because the product of two irrational numbers is not always an irrational number. c. the irrational number system is closed under multiplication, because the product of two irrational numbers is always an irrational number. d. the irrational number system is closed under multiplication, because the product of two irrational numbers is always a rational numbers. reset submit

Polynomials plz quick 1: subtract and simplify (–y^2 – 4y – 8) – (–4y^2 – 6y + 3)