First - 8
second - 4
third - 12
fourth - 9
Answer:
Step-by-step explanation:
(1) 2x - 6y = -12
(2) x + 2y = 14
There is a -6y and a +2y. Since they have opposite signs, I'll try to eliminate the y terms. (That's my choice. There is more than one way to solve these.)
Multiply eq. (2) by 3:
3x + 6y = 42
Then add the result to eq. (1) to eliminate the y terms:
2x - 6y = -12
3x + 6y = 42
------------------
5x = 30, so x = 6
Now plug the value of x into eq. (2) and solve for y:
6 + 2y = 14
2y = 8
y = 4
Why did I use eq. (2) to solve for y? Because it's less work. I could have used eq. (1) instead:
2(6) - 6y = -12
12 - 6y = -12
-6y = -24
y = 4
More than one way to solve.
Answer:
94 cm
Step-by-step explanation:
Set up and solve an equation of ratios:
wingspan length
60 meters 70.5 m
----------------- = ----------------
80 cm x
Cross multiplying:
(60 m)x = (70.5 m)(80 cm)
Solve for x by dividing both sides of this equation by 60 m:
x = (70.5 m)(80 cm) / (60 m) = 94 cm
The length of the model should be 94 cm.
Answer: Simple interest rate = 3%.
Step-by-step explanation: We are given invested amount = $5000.
Number of years of investment = 4 years.
Interest earned = $600.
Simple interest formula.
I = P R T.
Where I is the earned interest, P is the invested amount , R is the rate of interest and T is the time in years.
Plugging values in formula, we get
600 = 5000 × R × 4
600 = 20000R.
Dividing both sides by 20000, we get
0.03 = R.
Multiplying by 100 to convert it in percentage, we get
0.03 × 100 = R
R = 3 %.
