Hello from MrBillDoesMath!
Answer:
The lines do not intersect
Discussion:
Where do the lines intersect?
5x + 4 = 5x - 3 => subtract 5x from both sides
4 = -3 => NO WAY! The lines do not intersect
Thank you,
MrB
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 :)
Given:
The measurement of the angles of a triangle are 3b,2b,and 4b.
To find:
The smallest angle.
Solution:
According to the angle sum property, the sum of all angles of a triangle is 180 degrees.
[Angle sum property]

Divide both sides by 9.

Now,



Therefore, the smallest angle is 40 degrees.
2 and 37/100 so I'm pretty sure yes it can be simplified
Cut out 18%
100=all,
all-cut out=remaining
100-18=82
4hrs 20mins=240+20mins=260mins
82% of 260 is 0.82*20=213.2=3 hours and 33.2 minutes
he can runi s 3 hours and 33.2 minutes