Answer:
(d)
Step-by-step explanation:
Elimination is a good choice of solution method when the coefficient of a variable in one equation is a simple multiple of the coefficient of that same variable in the other equation. This is the case for the system in the last choice. (see attached)
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We can consider the alternatives:
(a) substitution for y would work well
(b) the solution is given, no solution effort is required
(c) substitution for y would work well
(d) elimination would work well.
3(2x +3y) +(-6x +y) = 3(18) +(12) . . . . . eliminates x (y=6.6)
(2x +3y) -3(-6x +y) = (18) -3(12) . . . . . . eliminates y (x=-0.9)
Answer:
230cm²
Step-by-step explanation:
The shape can be split into two shapes horizontally: a triangle and a rectangle.
<u>Area of the rectangle</u>
The area of a rectangle = length × width
In this case, the length is 20cm and the width is 7cm. 20 × 7 = 140cm²
<u>Area of the triangle</u>
The area of a triangle = 1/2 × base × height
In this case, the base is 20cm and the height is 9cm (16cm - 7cm). 1/2 × 20 × 9 = 90cm²
<u>Area of the shape</u>
To find the area of the total shape, we can add 140cm² and 90cm² to get 230cm².
Hope this helps!
Answer:
- width: 18 in
- length: 27 in
Step-by-step explanation:
The relations between length (L) and width (W) are ...
W +9 = L
LW = 486
Substituting gives ...
(W+9)W = 486
W^2 +9W -486 = 0 . . . put in standard form
(W +27)(W -18) = 0 . . . . factor
W = 18 . . . . the positive solution
The width of the rectangle is 18 inches; the length is 27 inches.
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<em>Comment on factoring</em>
There are a number of ways to solve quadratics. Apart from using a graphing calculator, one of the easiest is factoring. Here, we're looking for factors of -486 that have a sum of 9.
486 = 2 × 3^5, so we might guess that the factors of interest are -2·3² = -18 and 3·3² = 27. These turn out to be correct: -18 +27 = 9; (-18)(27) = -486.
The reduction from of the equation is .
<h2>
Given that</h2>
Reduce the equation; by .
<h3>According to the question</h3>
To reduce the given equation follow all the steps given below.
Reduce the equation; by .
To reduce the equation means we need to subtract one equation from another.
Then,
The reduction from the equation is,
Hence, the reduction from of the equation is .
To know more about Subtraction click the link is given below.
brainly.com/question/26182329