5x+7y=25
5x-2y=-65
subtract both of the equations
5x-5x=0
7y--2y= 7y+2y=9y
25--65=25+65=90
0+9y=90
9y=90
divide both sides by 9 to get y by itself
9y/9=90/9
cross out 9 and 9 which becomes 1*1*y=y
90/9=10
y=10
find x by using the substitution method
5x+7y=25
5x+7(10)=25
5x+70=25
move +70 to the other side
sign changes from +70 to -70
5x+70-70=25-70
5x=-45
divide both sides by 5 to get x by itself
5x/5=-45/5
cross out 5 and 5 then becomes 1*1*x=x
-45/5=-9
x=-9
answer:
(-9,10)
Answer:
The results don't make sense
Step-by-step explanation:
We can solve by means of a 2x2 system of equations, we have to:
"x" is the number of children's tickets
"y" is the number of adult tickets
Thus:
8 * x + 8.75 * y = 259
x + y = 35 => x = 35 - y
replacing we have:
8 * (35 - y) + 8.75 * y = 259
280 - 8 * y + 8.75 * y = 259
- 8 * y + 8.75 * y = 259 - 280
0.75 * y = -21
y = -21 / 0.75
y = -28
Thus:
x = 35 - (-28) = 63
With these results we notice that the problem has inconsistency, since the value of the tickets cannot be given a negative number, I recommend reviewing the problem, since the approach is correct.
Answer:
C] 13 units
Step-by-step explanation:
No it is not correct the answer is 14!
Answer:
or ![(-\infty, 47/6]](https://tex.z-dn.net/?f=%28-%5Cinfty%2C%2047%2F6%5D)
Step-by-step explanation:
Note that
.
Also, note that
.
So, the inequality is really equal to
.
We can then add
to both sides to get
.
So, the solution is
, or in interval notation, ![(-\infty, 47/6]](https://tex.z-dn.net/?f=%28-%5Cinfty%2C%2047%2F6%5D)