Answer:

You can plug it into a graphing website or calculator to double check
Answer:
a. x = 14
b. Perimeter = 77
Step-by-step explanation:
a. Based on the Triangle Proportionality Theorem:



Cross multiply


Add 2 to both sides


Divide both sides by 2
x = 14
b. Perimeter of ∆QRS = RQ + QS + RS = (2x - 2) + 13 + 17 + (21 - 7) + 7
Plug in the value of x
= (2(14) - 2) + 13 + 17 + 14 + 7
= 26 + 13 + 17 + 14 + 7
= 77
I think the best way in memorizing the roots of numbers 1 - 30 is by through methods that would suitable for you but you must consider is the pattern in each number or the square, every number has it pattern and i know you realized it by now. I hope this would help
1 yr = 12 months
4 yrs= 12x4 = 48 months
3/4 year= 3/4 x12 = 9
so 4 3/4 years= 48+9 =57 months