51:45 Triangle PQR is reflected across a line, P=(4,-5), and P'=(-4,-5). What is the line of reflection?
the x-axis
SEES
✓X
the y-axis
the line y = x
the line y = -X

On a piece of paper graph y < 3x

One of the same side angles of two parallel lines is 20° smaller than the other one. find the measures of these two angles.

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.