The average of four numbers is 85. if three of the numbers are 76,78,and 81, what is the fourth number

Step-by-step explanation:

x = 4th number

y = sum of first three numbers

y = 76 + 78 + 81

y = 235

x = 85*4 - 235

x = 105

The sum of the 4 numbers is 85*4= 340. To get the other number, you do 340-(76+78+81) to get 340-235=105

ANSWER:340-235=105

a

step-by-step explanation:

hello,

as we don't know if g(x) is continue,

answer b

f(x)=2x²-8x+1=2(x²-4x+4)+1-8=2(x-2)²-7

vertex is (2,-7) ( a minimum since coefficient of x² is > 0)