Answer:
16
Step-by-step explanation:
-4(16+5)
5+16=20
20 sub -4 = 16
Did you notice the little box with corners marked in the angle down at the bottom ?
That angle is a right angle, and <em>this triangle is a right triangle</em> !
This piece of information is a big help. It breaks the problem wide open.
You know that in order to find the longest side of a right triangle . . .
-- Square the length of one short side.
-- Square the length of the other short side.
-- Add the two squares together.
-- Take the square root of the sum.
One short side=48. Its square = 2,304.
The other short side=48. Its square = 2,304.
Add the two squares: 2,304 + 2,304 = 4,608
The square root of the sum = √4,608 = <em><u>67.88</u></em> (rounded)
Answer: the cost per unit of gas is $0.28
Step-by-step explanation:
Let x represent the cost per unit of electricity.
Let y represent the cost per unit of gas.
During one month, a homeowner used 500 units of electricity and 100 units of gas for a total cost of $333. This is expressed as
500x + 100y = 333 - - - -- - -- - -- -1
The next month, 400 units of electricity and 150 units of gas were used for a total cost of $286. This is expressed as
400x + 150y = 286 - - - - - - - - - --2
Multiplying equation 1 by 400 and equation 2 by 500, it becomes
200000x + 40000y = 133200
200000x + 75000y = 143000
Subtracting, it becomes
- 35000y = - 9800
y = - 9800/- 35000
y = 0.28
Substituting y = 0.28 into equation 2, it becomes
400x + 150 × 0.28 = 286
400x = 286 - 42 = 244
x = 244/400 = 0.61
