9514 1404 393
Answer:
47 -6√10
Step-by-step explanation:
As you know, the area of a square is the square of the side length. It can be helpful here to make use of the form for the square of a binomial.
(a -b)² = a² - 2ab + b²
(√2 -3√5)² = (√2)² - 2(√2)(3√5) + (3√5)²
= 2 - 6√10 + 3²(5)
= 47 -6√10
__
<em>Check</em>
√2-3√5 ≈ -5.29399 . . . . . . . . note that a negative value for side length makes no sense, so this isn't about geometry, it's about binomials and radicals
(√2-3√5)² ≈ 28.02633
47 -6√10 ≈ 28.02633
Answer:
It's the last choice:
2x + y - 1 = 0.
Step-by-step explanation:
x - 2y - 3 = 0
Convert to slope-intercept form in order to find the slope:
-2y = -x + 3
y = 1/2x - 3/2
So the slope is 1/2. The slope of a line perpendicular to this is -1 / 1/2 = -2.
Using the point-slope form to find the required equation:
y - y1 = m(x - x1)
x = 4 and y = -7 so we have:
y + 7 = -2(x - 4)
y + 7 = -2x + 8
2x + y - 1 = 0 is the answer.
