Answer:
20
Step-by-step explanation:
→ First find the value of x and y
x + y = 5
x - y = 4
→ Add the equations to cancel out the y's
2x = 9
→ Divide both sides by 2 to find the value of x
x = 4.5
→ Substitute x = 4.5 back into x - y = 4 to find the value of y
4.5 - y = 4
→ Minus 4.5 from both sides to isolate -y
-y = -0.5
→ Multiply everything by -1
y = 0.5
→ Substitute x = 4.5 and y = 0.5 into x² - y²
4.5² - 0.5² = 20.25 - 0.25 = 20
Answer:
The answer is B!
Step-by-step explanation:
Add 1 to both sides, then divide 80 by 9!
Answer:
c)
Step-by-step explanation:
Use 49 instead of 14 for 7²
Reason: 7² = 7 * 7 = 49
Not 14 as 7*2 = 14
Answer: 14.73
Step-by-step explanation:
The given triangle is a right angle triangle.
EF^2 + DF^2 = ED^2
The hypotenuse is |ED| while the two shorter legs are |EF| and |DF|.
We can then apply the Pythagoras Theorem to find the length of EF.
(EF)^2 + (DF)^2 = (ED)^2
(EF)^2 + (12)^2 = (19)^2
(EF)^2 + 144 = 361
(EF)^2 = 361 - 144
(EF)^2 = 217
EF = 14.73
Answer:
Probability that a randomly selected student plays sport and is in band = 1/50
Step-by-step explanation:
Total number of students= 1900
Percentage of those that play sport and are in band = 2%
Hence those that play sport and are in band = 2/100 x 1900 = 38 students
Probability that a randomly selected student plays sport and is in band = 38/1900 = 1/50