Answer:
Given that,
R = 3x + 9y
Also, given that,
y = 6
R = 7
We have to find the value of x
For that, you can to put 6 and 7 to the equation instead of y and R respectively.
R = 3x + 9y
7 = 3x + 9 × 6
7 = 3x + 54
7 - 54 = 3x
- 47 = 3x

Hope this helps you :-)
Let me know if you have any other questions :-)
Nicky won two races. One third of six is 2
Answer:
7 years
Step-by-step explanation:
Given that:
Let Richard's age = x
Elder sister's age = 2x
Youngwr sister's age = x - 2
Product of sisters ages = 70
2x * (x - 2) = 70
2x² - 4x = 70
2x² - 4x - 70 = 0
x² - 2x - 35 = 0
x² - 7x + 5x - 35 = 0
x(x - 7) +5(x - 7) = 0
(x - 7) or (x + 5) = 0
x = 7 or x = - 5
X can't be negative
Hence, x = 7
Richard is 7 years
Answer: a=14
Step-by-step explanation:
Equation: 5=1/2a-2