Answer:
x=112
Step-by-step explanation:
x/2-18=38
first add +18
x/2=56
now multiply by 2
x=112
Answer:
The value of x and y that satisfy the equations is x = 2 and y = 1
Step-by-step explanation:
Given
2.5(x−3y)−3=−3x+0.5
3(x+6y)+4=9y+19
Required.
Find x and y
We start by opening all brackets
2.5(x−3y)−3=−3x+0.5 becomes
2.5x - 7.5y - 3 = -3x + 0.5
Collect like terms
2.5x + 3x - 7.5y = 3 + 0.5
5.5x - 7.5y = 3.5 ---- Equation 1
In similar vein, 3(x+6y)+4=9y+19 becomes
3x + 18y + 4 = 9y + 19
Collect like terms
3x + 18y - 9y = 19 - 4
3x + 9y = 15
Multiply through by ⅓
⅓ * 3x + ⅓ * 9y = ⅓ * 15
x + 3y = 5
Make x the subject of formula
x = 5 - 3y
Substitute 5 - 3y for x in equation 1
5.5(5 - 3y) - 7.5y = 3.5
27.5 - 16.5y - 7.5y = 3.5
27.5 - 24y = 3.5
Collect like terms
-24y = 3.5 - 27.5
-24y = -24
Divide through by - 24
y = 1
Recall that x = 5 - 3y.
Substitute 1 for y in this equation
x = 5 - 3(1)
x = 5 - 3
x = 2
Hence, x = 2 and y = 1
Suppose:
C=cost
c=cost per kilo-watt hour
w=number of watts
h=number of hours
thus
C=kwhc
where:
k=constant of proportionality:
k=C/(whc)
but
C=15 when w=6000, h=10/60=1/6 hours, c=7.5 cents per kw/h
thus
k=15/(6000*1/6*7.5)
k=0.002
thus:
C=0.002(whc)
hence:
when
h=70*2=140=140/6=70/3 hours the cost will be:
C=0.002(6000*70/3*7.5)
C=2100 cents
C=$21
Answer: multiply 10 to both terms and subrtact products
Step-by-step explanation:
10(5 - 2x)
multipy 10 to both terms
50 20x
subtract products
50 - 20x