<em>f(-5) = 15 (A)</em>
- Step-by-step explanation:
<em>f(x) = - 2x + 5</em>
<em>replace x = - 5</em>
<em>f(-5) = -2(-5) + 5
</em>
<em>(-)(-) = +
</em>
<em>f(-5) = 10 + 5
</em>
<em>f(-5) = 15 (A)</em>
0. We have 4/6, 36/8, and 12/18
1. Simplify the fractions: 2/3, 9/2, 2/3
2. Order them: 4/6 and 12/18, 36/8
Answer:
(x, y) = (1, -1)
Step-by-step explanation:
We'll write these equations in general form, then solve using the cross-multiplication method.
43x +67y +24 = 0
67x +43y -24 = 0
∆1 = (43)(43) -(67)(67) = -2640
∆2 = (67)(-24) -(43)(24) = -2640
∆3 = (24)(67) -(-24)(43) = 2640
These go into the relations ...
1/∆1 = x/∆2 = y/∆3
x = ∆2/∆1 = -2640/-2640 = 1
y = ∆3/∆1 = 2640/-2640 = -1
The solution is (x, y) = (1, -1).
_____
<em>Additional comment</em>
The cross multiplication method isn't taught everywhere. The attachment explains a bit about it. Our final relationship changes the order of the fractions to 1, x, y from x, y, 1. That way, we can use the equation coefficients in their original general-form order. (The fourth column in the 2×4 array of coefficients is a repeat of the first column.)
Secθ = cos^(-1)θ is the same as secθ = 1/cosθ
<span>Secant is a trigonometric function, reciprocal to the cosine
</span>
Answer:
the third term wasn't distributed properly the -2 has to multiply by +2 = -4
Step-by-step explanation:
-5x^2y - 3xy^2 - 2(4y+2) - 2.5x^2y
-5x^2y - 3xy^2 - 8y - 4 - 2.5x^2y
-7.5x^2y - 3xy^2 - 8y - 4