First picture)
I: 5x+2y=-4
II: -3x+2y=12
add I+(-1*II):
5x+2y-(-3x+2y)=-4-12
8x=-16
x=-2
insert x=-2 into I:
5*(-2)+2y=-4
-10+2y=-4
2y=6
y=3
(-2,3)
question 6)
I: totalcost=115=3*childs+5*adults
II: 33=adults+childs
33-adults=childs
insert childs into I:
115=3*(33-adults)+5*adults
115=99-3*adults+5*adults
16=2*adults
8=adults
insert adults into II:
33-8=childs
25=childs
so it's the last option
question 7)
a) y<6 and y>2 can also be written as 2<y<6, so solution 3 exist for example
b) y>6 and y>2 can also be written as 2<6<y, so solution 7 exist for example
c) y<6 and y<2 inverse of b: y<2<6, so for example 1
d) y>6 and y<2: y<2<6<y, this is impossible as y can be only either bigger or smaller than 2 or 6
so it's the last option
question 8)
I: x+y=12
II: x-y=6
subtract: I-II:
x+y-(x-y)=12-6
2y=6
y=3
insert y into I:
x+3=12
x=9
(9,3)
question 9)
I: x+y=6
II: x=y+5
if you take the x=y+5 definition of II and substitute it into I:
(y+5)+y=6
which is the second option :)
The result after combining like terms is: 
Step-by-step explanation:
Given expression is:

The like terms are those terms with whom the variable or product of variables is same.
As in the given expression, first and third, both terms have x^2y so both terms are like terms
Combining like terms, means the indicated operation is performed on them
So,
Combining like terms:

Hence,
The result after combining like terms is: 
Keywords: Expressions, polynomials
Learn more about polynomials at:
#LearnwithBrainly
Answer:
A, B, E area ll less than 0
Step-by-step explanation:
They are all negative numbers.
Answer:
2x+50 and 5x-55 both are congruent or have same measure.
Step-by-step explanation:
Since we want to prove that both lines are parallel, this means no theorems that involve with parallel lines apply here.
First of, we know that AC is a straight line and has a measure as 180° via straight angle.
x+25 and 2x+50 are supplementary which means they both add up to 180°.
Sum of two measures form a straight line which has 180°.
Therefore:-
x+25+2x+50=180
Combine like terms:-
3x+75=180
Subtract 75 both sides:-
3x+75-75=180-75
3x=105
Divide both sides by 3.
x=35°
Thus, x = 35°
Then we substitute x = 35 in every angles/measures.
x+25 = 35°+25° = 60°
2x+50 = 2(35°)+50° = 70°+50° = 120°
5x-55 = 5(35°)-55 = 175°-55° = 120°
Since 2x+50 and 5x-55 have same measure or are congruent, this proves that both lines are parallel.