Arwen travels at an average speed of 30 mph for 40 miles. Without stopping, Arwen then travels 60 miles in 1.75 hours.
Find her average speed for the entire journey to 2 dp.

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116

d. corresponding side lengths in similar triangles are proportional in length.

step-by-step explanation: