Step-by-step explanation:
length = width + 4
length×width = 77
using the first in the second equation
(width + 4)×width = 77
width² + 4width = 77
now, what square or squaring factors can create this ?
we are looking for (width + a)(width + b).
we know, this is
width² + (a+b)width + ab
so, what a, b can create 4 (the factor in our actual equation) ?
1, 3 and 2, 2, if we are only looking at whole numbers.
and which of the possibilities can we use to turn 77 into a square number ?
81 is only 4 away ...
2+2 = 4.
aha !
so, we can actually say our equation is
width² + 4width + 4 = 77 + 4
and then
(width + 2)² = 81
width + 2 = 9
width = 7 m
length = width + 4 = 7 + 4 = 11 m
Answer:
Step-by-step explanation:
Answer:
b. y-y1 = m(x-x1)
Step-by-step explanation:
It's a matter of definition. There are perhaps a dozen useful forms of equations for a line. Each has its own name (and use). Here are some of them.
- slope-intercept form: y = mx + b
- point-slope form: y -y1 = m(x -x1)
- two-point form: y = (y2-y1)/(x2-x1)(x -x1) +y1
- intercept form: x/a +y/b = 1
- standard form: ax +by = c
- general form: ax +by +c = 0
Adding y1 to the point-slope form puts it in an alternate form that is useful for getting to slope-intercept form faster: y = m(x -x1) +y1. I use this when asked to write the equation of a line with given slope through a point, with the result in slope-intercept form.
The answer is 104.
1/4 of 104 is 26, 104 - 26 = 78
78 - 7 = $71
D is the answer to your question
