Which organ system contains the skin, hair, fingernails and sweat glands? 

Simplify the expression by combining like terms.7a – 2a + a – 15

Multiply.7(-2)

Simplify the expression. Use the distributive property to remove any parentheses.9(6n + 5)

Multiply.-2 ∙ 8

Subtract.2 – 6

Subtract.-10 – (-9)

Solve the equation.8 = b – 16

Solve the equation.2r + 7 = 25

Subtract.-2 – (-2)