Elimination:
7x - 3y = 20
5x + 3y = 16
(add)
12x = 36
÷ 12
x = 3
(5 × 3) + 3y = 16
15 + 3y = 16
- 15
3y = 1
÷ 3
y = 1/3
Substitution:
5x + 3y = 16
- 3y
5x = 16 - 3y
÷ 5
x = 3.2 - 0.6y
5(3.2 - 0.6y) + 3y = 16
16 - 3y + 3y = 16
16 = 16
- 16
6y = 0
÷ 6
y = 0
Sorry the substitution messed up for some reason, I'll fix it after I've answered the other question
Check the picture below.
to get the equation of any straight line, we simply need two points off of it, so let's use those in the picture


Answer: D(x) = 2kg/h*x
where x is the number of hours.
Step-by-step explanation:
The information that we have is:
in 5 hours, we can prepare 10kg of dough.
With this, we can find the rate per hour, to do this we find the quotient:
R = 10kg/5h = 2kh/h
This meeans that in one hour, we can make 2kg of dough.
Then, in x hours, we can make x times 2kg of dough, then the equation will be:
D(x) = 2kg/h*x
where x is the number of hours.
Answer: 1.7 is the answer hope this helps.
Step-by-step explanation:
The water tower is 62.8 meters tall :))