Solve the system of equations using substitution:
ſx + 4y = 15
(2x – y=-15

Christina can paint 420 square feet in 105 minutes. which unit rate describes the scenario?

The ph level of a blueberry is 3.1 what is the hydrogen-ion concentration [h+] for the blueberry

Select the correct answer from each drop-down menu. consider the following polynomials equations. 3x^2(x-1) and -3x^3+ 4x^2-2x+1 perform each operation and determine if the result is a polynomial. is the result of a + b a polynomial? yes or no is the result of a - b a polynomial? yes or no is the result of a · b a polynomial? yes or no