find the value of" A" such that triangle DEF with vertices D (a,1) , E(10,7) and F(7 ,11) is a right angle at E?​

a=2

(m1) slope of DE=(7-1)/(10-a)=6/(10-a)

(m2) slope of EF=(11-7)/(7-10)=4/-3=-4/3

since line are perpendicular

m1m2=-1

6/(10-a) ×-4/3=-1

6/(10-a)=3/4

6×4=3(10-a)

24=30-3a

3a=30-24

a=6/3=2

answer: the value should be used for i in the formula of calculation the monthly payment , the interest rate per period is 0.85.

step-by-step explanation:

the given rate of interest i= 85%

in calculating the monthly payment for a loan with an interest rate compounded monthly, the value of the interest rate per period we use in the formula must be in decimal form.

to convert it in decimal, we divide it by 100, we get

hence, the value should be used for i in the formula of calculation the monthly payment , the interest rate per period is 0.85.

answe: it will take 4.5 hours for naomi and clair to paint an equal number of square feet

hope i

-lavira : )