Solve. 3
b=-a
a + b = 21
a = 37
a =
a = 20
a = 12
b = 9
a = 20
b = 11
b = 15
1
b = -16

Will mark brainliest if you answer ! the taco shop sold 198 lunches friday. this number is 3 more than 3 times the number they sold monday. let n represent the number of lunches sold monday. which equation shows an equality between two different ways of expressing the number of lunches sold on friday? a. n – 3 = 198 b. 3n – 3 = 198 c. 3n + 3 = 198 d. n + 3 = 198

Mary beth used the mapping rule to find the coordinates of a point that had been rotated 90° counterclockwise around the origin. examine the steps to determine whether she made an error. m (3, –6) is rotated 90° counterclockwise. (x, y) → (–y, x) 1. switch the x- and y-coordinates: (6, –3) 2. multiply the new x-coordinate by –1: (6(–1), –3) 3. simplify: (–6, –3) .

Emily is entering a bicycle race for charity. her mother pledges $0.90 for every 0.75 mile she bikes. if emily bikes 18 miles, how much will her mother donate?