Andrea wanted to know how much farther she ran on Tuesday than on Monday. Her work is below.

What mistake did Andrea make when solving the problem?
A. She did not align the decimal points.
B. She did not rename correctly.
C. She added instead of subtracted.
D. She did not subtract 15 and 6 correctly.

x = -2

y = 848

step-by-step explanation:

plug in the numbers

6 spoons of sugar for every 21 cups of flour

step-by-step explanation:

see explanation

step-by-step explanation:

a

(6r + 7) + (13 + 7r) ( remove brackets and collect like terms )

= 6r + 7 + 13 + 7r

= 13r + 20

b

remove brackets and collect like terms

13 - r - 1 + r

= 12 - r

c

remove brackets and collect like terms

= - 8 - r + 2r - 4

= - 12 + r

d

remove brackets and collect like terms

= 7r - - - 6r

[-   - = - - = - ]

= r -