All categories

2 years ago

Solve the simultaneous equations 3x + 2y = 30 3x - y = 21

Mathematics

1 answer:

Mrac [35]2 years ago

3 0

Answer:

x = 8 , y = 3

Step-by-step explanation:

3x + 2y = 30

3x - y = 21 -> y = 3x - 21

3x + 2 (3x - 21) = 30

3x + 6x - 42 = 30

3x + 6x = 30 + 42

9x = 72

x = 72/9 = 8

y = 3*8 - 21 = 24 - 21 = 3

∴ x = 8 & y = 3

You might be interested in

4. (10 points) From the given triangle:

katrin2010 [14]

Answer:

sinθ = y/r sinθ = $\frac{-6}{10} = \frac{-3}{5}$

cosθ = x/r cosθ = $\frac{8}{10} = \frac{4}{5}$

tanθ = y/x tanθ = $\frac{-6}{8} =\frac{-3}{4}$

cscθ = r/y cscθ = $\frac{-5}{3}$

secθ = r/x secθ = $\frac{5}{4}$

cotθ = x/y cotθ = $\frac{4}{3}$

explanation:

r = $\sqrt{(8)^{2}+(-6)^{2} }$

r = 10

x = 8

y = -6

r = $\sqrt{(4)^{2}+(3)^{2} }$

r = 5

x = 4

y = 3

7 0

2 years ago

What is 7/10 - 5/12???? PLEASE HELP

Anarel [89]

Answer:

17/60

Step-by-step explanation:

5 0

2 years ago

Read 2 more answers

2x−8=20 steps to solving

Art [367]

Add 8 to both sides
2x = 28
Divide 2 to both sides
Solution: x = 14

4 0

2 years ago

Read 2 more answers

A direct variation includes the points (4,16) and (1,n). Find n.

vladimir2022 [97]

Answer: n=4

Step-by-step explanation: 4/4=1 and 16/4=4 (1,4) n=4

7 0

2 years ago

A recipe whuch makes 8 servings calls for 2 cups if sugar. How many cups if sugae will it takr to make 18 servings

yan [13]

Answer:
4.5 cups of sugar
Explanation:
set up the problem like servings/cups. it would look like 8/2. then add the 18 servings and make it 8/2=18/x so you can cross multiply. cross multiply and you get 8x=36. divide it by 8 and you get x=4.5 cups. hope this helps!

3 0

2 years ago