Solve the math problem

Which addition property is being illustrated below? (type commutative or associative) (6 + 7) + 1 = 6 + (7 + 1)

Write the slope-intercept form of the line that passes through the point (1, 0) and is parallel to x - y = 7. t

Aswimming pool had 2.5 million liters of water in it. some water evaporated, and then the pool only had 22 million liters of water in it. what percent of the water evaporated?