Answer:
square root of 65
Step-by-step explanation:
all i am going to say is, Pythagorean theorem.
Answer:

________

Step-by-step explanation:
Given

Line up the numbers

Multiply the top number by the bottom number one digit at a time starting with the ones digit left(from right to left right)
Multiply the top number by the bolded digit of the bottom number

Multiply the bold numbers: 1×4=4

Multiply the bold numbers: 2×4=8

Multiply the top number by the bolded digit of the bottom number

Multiply the bold numbers: 1×1=1

Multiply the bold numbers: 2×1=2

Add the rows to get the answer. For simplicity, fill in trailing zeros.

adding portion

Add the digits of the right-most column: 4+0=4

Add the digits of the right-most column: 8+1=9

Add the digits of the right-most column: 0+2=2

Therefore,

________

85 x 3 = 255
first 2 test grades were 81 and 86:
81 + 86 = 167
Need to find the 3rd to have exact average 85:
255 - 167 = 88
So her 3rd test needs to make 88 to make average of 85
Double check: 81 + 86 + 88 = 255 = 85 + 85 + 85
Sorry dont know, any thing else you need help with?
Answer:
7,600
Step-by-step explanation:
both parents invest 7,600.
7,600x2= 15,200
there are 2 girls so divide 15,200 by 2 and u get 7,600