Ok so you do 3x7= 21 which you already know. So then you do 1x7=7. Last, you just add 21+7=28 pens in total
His work should have looked like this.
2x + y = 5
x − 2y = 10
y = 5 − 2x
x − 2(5 − 2x) = 10
x − 10 + 4x = 10
5x − 10 = 10 When he added in both sides, he subtracted 10 from 10,
5x = 20 instead of adding 10 from 10 to make 20.
x = 4
2(4) + y = 5
8 + y = 5
y = -3
Multiply everything in the parenthesis by 3.
9x - 24 = 4x + 6
Add 24 to both sides.
9x = 4x + 30
Subtract 4x from both sides.
5x = 30
Divide both sides by 5.
x = 6
Hope this helps!
Answer:
1
Step-by-step explanation:
everything rise 0 power is 1.
Answer:$1.25
Step-by-step explanation:
2 divided by 1.60=$1.25
3 divided by 2.40= $1.25
5 divided by 4.00= $1.25
8 divided by 6.40 = $1.25