Answer:
2A/h = b
Step-by-step explanation:
The formula for area of a triangle is
A = 1/2 bh
Multiply each side by 2
2A = 2*1/2 bh
2A = bh
Divide each side by h
2A/h = bh/h
2A/h = b
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
Answer:
x=5, y=3
Step-by-step explanation:
1) x+3y=14,4x+5y=35
2) x+3y=14
3) x=-3y+14
4) 4(-3y+14)+5y=35
5) -12y+56+5y=35
6) -7y+56=35
7) -7y=-21
8) y=3
9) x=-3\times 3+14
10) x=-9+14
11) x=5
finale and last : x=5,y=3 ✅
Answer:
D 81 pi units^2
Step-by-step explanation:
The circumference of a circle is given by
C = 2 * pi *r
18 pi = 2 * pi *r
Divide each side by 2 * pi
18 pi / (2 pi) = 2 pi * r/ (2 pi)
9 = r
Now we can find the area. Area is given by
A = pi r^2
A = pi * 9^2
A = 81 pi units^2
