Alex simplified the expression 7+(3x 1.4)+5+2+(5x1.4) to find the area of the figure on the grid. What error did Alex make?
He found the perimeter of the figure instead of the area.
He added the lengths of the lines creating the indentation instead of subtracting them.
He used 5x1.4 and 3 x 1.4 as the length of each diagonal line instead of 5 and 3.
He added the five lengths together instead of multiplying them.

all three statements are true

step-by-step explanation:

a shipping fee of 5% is charged online with every item purchased online

first let's just take each option and calculate them based on this, to see if the answers matched

keith buys a 40 dollar book

40 x 0.05 = 2

therefore there will be a two dollar fee on keith's book

40 + 2 =42

the first statement is true

a chair costs $80

80 x 0.05 = 4

80 + 4 = 84

the second statement is true

george buys a 20 dollar calculator

20 x 0.05 = 1

20 + 1 = 21

the third statements are true

all three statements are true