Answer:Mark Is 9 years old; Christine is 5 years old
Step-by-step explanation:
Present age
LET mark age be x
Christine be x-4 yrs
In 3 yrs Time
Mark will be x+3 yrs old
Christine will be (x -4 +3) = x-1 years old
Also, In 3 years time
Christine = 2/3 Mark
such that
x-1 = 2/3(x+3)
x -1= 2x+6 / 3
3x -3= 2x+6
3X--2X = 6+3
=X=9
Mark Is 9 years old
Christine is x -4 = 9-4=5 years old
I think it’s .22 I’m not sure hope this helps :)
Answer: -5+8 because the difference (-) of -5 and 8 is 8 - (- 5) which can also be expressed as -5+8. All that matters is that 5 stays negative and 8 stays positive.
2.5y + 3x = 27
5x - 2.5y = 5
Align the variables to make solving this easier.
2.5y + 3x = 27
-2.5y + 5x = 5
You can see that the 2.5y and -2.5y cancel each other out. Then add the 3x and 5x, and 27 + 5.
3x = 27
5x = 5
8x = 32
Divide both sides by 8.
x = 4
Now input that x into one of the equations to get y.
2.5y + 3(4) = 27
2.5y + 12 = 27
2.5y = 15
y = 6
The answer to this system of equations is x = 4, y = 6. (4, 6)
