Multiply each side by 2.5 than add for perimeter .
Answer:
a) x = 12 y = 9
b) x = -2 y = -4
c) x = 6 y = -2
Step-by-step explanation:
a)
Equation 1: 6x - 7y = 9
Equation 2: 3x + 2y = 54
Multiply Equation 2 by 2:
⇒ 6x + 4y = 108
Subtract equations:
6x + 4y = 108
<u>- 6x - 7y = 9 </u>
11y = 99
Divide both sides by 11:
⇒ y = 9
Substitute found value of y into Equation 1 and solve for x:
⇒ 6x - 7(9) = 9
⇒ 6x - 63 = 9
⇒ 6x = 72
⇒ x = 12
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b)
Equation 1: 4x - 5y = 12
Equation 2: 2x - 3y = 8
Multiply Equation 2 by 2:
⇒ 4x - 6y = 16
Subtract equations:
4x - 6y = 16
<u>- 4x - 5y = 12 </u>
-y = 4
Divide both sides by -1:
⇒ y = -4
Substitute found value of y into Equation 1 and solve for x:
⇒ 4x - 5(-4) = 12
⇒ 4x + 20 = 12
⇒ 4x = -8
⇒ x = -2
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c)
Equation 1: 4x - 2y = 28
Equation 2: 3x + 3y = 12
Multiply Equation 1 by 3:
⇒ 12x - 6y = 84
Multiply Equation 2 by 4:
⇒ 12x + 12y = 48
Subtract equations:
12x - 6y = 84
<u>- 12x + 12y = 48 </u>
-18y = 36
Divide both sides by -18:
⇒ y = -2
Substitute found value of y into Equation 1 and solve for x:
⇒ 4x - 2(-2) = 28
⇒ 4x + 4 = 28
⇒ 4x = 24
⇒ x = 6
The score is given by:
z=(x-mean)/s.d
In the question above:
x=1300
mean=1200
s.d=200
Thus:
z=(1300-1200)/200
=100/200
=0.5
The answer is 0.5
Answer:Biomaterial
Step-by-step explanation:
He did better in the geo test
28/40 x 100 to give a % = 70%
39/60 =65%
