Answer:
15
Step-by-step explanation:
Let x represent the number of algebra problems. Then the number of geometry problems was 27-x and the total working time was ...
2x +5(27 -x) = 90
-3x = 90 -135 . . . . subtract 135
x = -45/-3 = 15 . . . divide by -3
Rob had 15 algebra problems for homework.
Answer:a
Step-by-step explanation:
throughout the table it is presented that the answer, A, is correct becuase within the percentages is is obvious that a is correct.
Answer:
80 m^2
Step-by-step explanation:
The given information lets you write two equations involving length (x) and width (y).
- 2(x +y) = 36 . . . . the perimeter is 36 m
- (x+1)(y+2) -xy = 30 . . . . increasing the length and width increases area
The second of these equations simplifies to another linear equation, giving a system of linear equations easily solved.
xy +y +2x + 2 -xy = 30
2x +y = 28 . . . . . . . subtract 2
Dividing the first equation by 2 gives
x +y = 18
and subtracting this from the above equation gives ...
(2x +y) -(x +y) = 28 -18
x = 10
Then
y = 18 -10 = 8
The area of the original rectangle is xy = 10·8 = 80 m^2.
Answer: 35
Step-by-step explanation:
Answer:
19 4/5
Step-by-step explanation: