Mary has $135 to spend on clothes. She wants to purchase winter boots for $70 and some sweaters that cost $20 each. Write an inequality that represents Mary's situation and then solve the inequality.

The average human heart beats 1.15 \cdot 10^51.15⋅10 5 1, point, 15, dot, 10, start superscript, 5, end superscript times per day. there are 3.65 \cdot 10^23.65⋅10 2 3, point, 65, dot, 10, start superscript, 2, end superscript days in one year. how many times does the heart beat in one year? write your answer in scientific notation, and round to one decimal place.

The base of a triangle exceeds the height by 9 inches. if the area is 180 square inches, find the length of the base and the height of the triangle.

What are the solutions of the system? solve by graphing. y = -x^2 - 3x + 2 y = -2x + 2