Answer:
Percentage of computers working equals:
90%
Step-by-step explanation:
Three of the thirty computers are out of service.
Number of computers working=30-3=27
Total computers=30
Percentage of working computers=
=
= 90%
Hence, Percentage of computers working is:
90%
Answer:
x + y = ±15
Step-by-step explanation:
Step 1: Write out systems of equations
x - y = 1
xy = 56
Step 2: Rearrange 1st equation
x = y + 1
Step 3: Substitution
(y + 1)y = 56
Step 4: Distribute
y² + y = 56
Step 5: Solve for <em>y</em>
y² + y - 56 = 0
(y - 7)(y + 8) = 0
y = -8, 7
Step 6: Plug in <em>y </em>to find <em>x</em>
x - 7 = 1
x = 8
x - (-8) = 1
x + 8 = 1
x = -7
Step 7: Find answer
x + y = ?
8 + 7 = 15
-7 + -8 = -15
So both 15 and -15 could be the answer.
Answer:
18
Step-by-step explanation:
Sum of x, y and z = 20 × 3
= 60
x-5+y+4+z-5 = 60-5+4-5
= 54
Mean of x-5, y+4 and z-5
= 54 ÷ 3
= 18
Answer:
31
Step-by-step explanation:
Evaluate following the order set out in the acronym PEMDAS
That is parenthesis, exponents, multiplication, division, addition, subtraction
Given
(5 + 1)² - (11 + 3² ) ÷ 4
= 6² - (11 + 9) ÷ 4
= 36 - 20 ÷ 4 ← division before subtraction
= 36 - 5
= 31
