(1) y= - x² - 4x + 9 and (2) y + 5x = - 7. Isolate y in (2); y= - 5x - 7 (3)
Since (1) and (3) have the same value or the same y, then we can write:
(1)=(3)
- x² - 4x + 9 = - 5x - 7
-x² - 4x + 9 + 5x +7 = 0
-x² + x + 16 = 0 OR x² - x - 16 = 0
Solve this quadratic equation:
x' = [-b+√(b²-4ac)]/(2a) and x" = [-b-√(b²-4ac)]/(2a)
x' = [+1+√(-1)² - 4(1)(-16)]/2 → x' = [1+√(1+64)]/2 → x' = [1+√65)]/2
x" = [+1-√(-1)² - 4(1)(-16)]/2 → x' = [1-√(1+64)]/2 → x' = [1-√65)]/2
x' = [1+√65)]/2 = + 4.5311
x" =[1-√65)]/2 = - 3.5311
The person will run 7.456 miles
The x intercept is the x value when y is 0.
So,
0 = 2/5x + 5
-5 = 2/5x
-25 = 2x
The x intercept is -25/2.
Answer:
we know that
16/4-----------> 8/2---------> 4/1
so
case 1)
64/16--------> 32/8-----> 16/4------> 8/2------> 4/1
the quantity (64/16) is proportional to 16/4
case 2)
6/1 is not 4/1
so
the quantity (6/1) is not proportional to 16/4
case 3)
5/1 is not 4/1
so
the quantity (5/1) is not proportional to 16/4
case 4)
48*12--------> 24/6-----> 12/3------> 4/1
the quantity (48/12) is proportional to 16/4
case 5)
4/1 is equal to 4/1
so
the quantity (4/1) is proportional to 16/4
Step-by-step explanation:
Answer: She has to score a minimum of 92 marks to take her average to 80
Step-by-step explanation:
Let the equation be
Three months total = 76 x 3 = 228
(x + 228) / 4 = 80
x + 228 = 80 x 4
x = 320 - 228
x = 92
