A. 38
Let X = seventh graders
6th graders are twice the number of 7th graders; therefore, 6th graders will be 2X.
The total number of students is 57.
2X + X = 57
3X = 57
X = 57 / 3
X = 19
IF X represents the 7th graders; there are 19 seventh graders present.
Since 6th graders are represented by 2X; Then, 2 * 19 = 38 is the number of 6th graders present.
Add both numbers to check: 19 + 38 = 57.
Answer:
ab + ac + a
Step-by-step explanation:
a(b+c+1) Distribute a to b, c, and 1
ab + ac + a
If length = x then width = x - 7
area = x(x -7) = 120
x^2 - 7x - 120 = 0
(x +8(x-15) = 0
x = -8 and 15
length must be positive so length = 15 ins
width = 15-7 = 8 ins
