Answer:
A) 21
Step-by-step explanation:
Mean:
(23 + 18 + 24 + 15 + 25)/5
105/5
21
Okay first set up the equation
x
--- -2 = 5.5
-3
add over the 2
x
--- = 7.5
-3
now you need to multiply the denominator by the answer
(-3)(7.5) = x
-22.5 = x
The simultaneous equations are
2x - 7y = 4 (1)
3x + y = -17 (2)
Write (2) as
y = - 3x - 17 (3)
Substitute (3) into (1).
2x - 7(-3x - 17) = 4
2x + 21x + 119 = 4
23x = -115
x = -5
This is the equation obtained after substituting y from the second equation into the first equation.
The solution for y is
y = -3(-5) - 17 = -2
Answer: x = -5
Note: The solution is x = -5, y = -2.
Answer:
the first expression
Step-by-step explanation:
