3x+5x+21=y
3x+5x=8x
8x+21=y
-21 -21
8x=y-21
8x÷8=x
y-21÷8=y-2.625
x= -2.625 + 0.125 y
I think that is right... :)
Answer:
9/8 or 1.125
Step-by-step explanation:
i hope this helps :)
Answer:
Step-by-step explanation:
1) For each situation to grow or decay by a constant percent rate, it must be exponential. Therefore, the correct examples are
A. The number of cars sold doubles every year. It is a 200% growth every year.
D. Each time you start a car engine the remaining engine life decreases by 0.0075%. A case of decay
E. The number of people creating cat videos increases by 15% percent every year.
F. Computer technology increases by a factor of 3 every five years.
2) this is a case of exponential decay. The expression for exponential decay is
y = b(1 - r)^t
y = final value
b = initial value
r = decay rate
t = time
Given that
r = 10% = 10/100 = 0.1
b = 50 kilograms
y = W kilograms
The relationship is
W = 50(1 - 0.1)^t
W = 50(0.9)^t
It depends on what variable you are tying to solve for first. Say you are trying to solve for x first and then y on the first problem you wrote.
In substitution you solve one of the equations for example with
6x+2y=-10
2x+2y=-10
you solve 2x+2y=-10 for x
2x+2y=-10
-2y = -2y (what you do to one side of the = you do to the other)
2x=-10-2y (to get the variable by its self you divide the # and the variable)
/2=/2 (-10/2=-5 and -2y/2= -y or -1y, they are the same either way)
x=-5-y
now you put that in your original equation that you didn't solve for:
6(-5-y)+2y=-10 solve for that
-30-6y+2y=-10 combine like terms
-30-4y=-10 get the y alone and to do this you first get the -30 away from it
+30=+30
-4y=20 divide the -4 from each side
/-4=/-4 (20/-4=-5)
y=-5
now the equation you previously solved for x can be solved for y.
x=-5-y
x=-5-(-5) a minus parenthesis negative -(- gives you a positive
-5+5=0
x=0
and now we have solved the problem. x=0 and y=-5
Answer:
26 yards = 78 ft square
78 × 78 = 6084 foot of surface area
Step-by-step explanation:
I think this is correct. Multiply 26y× 3 ft = (78)^2
