To solve this system by substitution, we must substitute in the value we are given for x in terms of y (the first equation) into the second equation. This is modeled below:
x = -8y - 15
2x + 5y = -8
2 (-8y - 15) + 5y = -8
Now, we should solve this new equation for y. To begin, we should use the distributive property to get rid of the parentheses on the left side of the equation and begin the simplification process.
-16y - 30 + 5y = -8
Next, we can combine like terms on the left side of the equation by adding together the two terms that both contain the variable y.
-11y - 30 = -8
Next, we should add 30 to both sides in order to move all of the constant (number) terms to the left side of the equation.
-11y = 22
After that, we should divide both sides of the equation by -11 in order to get the variable y alone.
y = -2
Now, we can substitute our value for y back into one of our original equations (it doesn't matter which one you choose; they will yield the same answer).
x = -8y - 15
x = -8(-2) - 15
To simplify, we should following the order of operations outlined by PEMDAS and compute the multiplication and then the subtraction.
x = 16 - 15
x = 1
Therefore, the answer to the system is x = 1 and y = -2, or (1,-2) when written as an ordered pair.
Hope this helps!
A right triangle will be formed with 2.2 km as the hypotenuse, 0.5 degrees as the angle, and an unknown height (see attachment).
Recall the trigonmetric ratios sine, cosine, and tangent that can be used for right triangles.
Sin<span>θ = opposite side/hypotenuse
</span>Cos<span>θ = adjacent side/hypotenuse
</span>tan<span>θ = opposite side / adjacent side
</span>θ (theta) refers to the angle (not the right angle). In this case, θ is the given angle of 0.5°.
In this problem, you will use sine because there is a side opposite to the angle (the unknown side h) and the hypotenuse, and sine relates those two sides.
Let the variable h represent the unknown opposite side, the height.
sin(0.5°) = h / (2.2km)
h = (2.2km)sin(0.5<span>°)
h = 0.019 kmHope I helped! If you have questions on any of the steps, please comment below.</span>
Answer:
x=27
Step-by-step explanation:
180-2x-40+180-3x+180-x-50+180-4x = 360
360-2x-40-3x+360-x-50-4x= 360
360-10x-90= 0
10x= 270
x= 27
D = k + 20
j = 3k - 120
d = j
k + 20 = 3k - 120
20 + 120 = 3k - k
140 = 2k
140/2 = k
70 = k.....so Katie weighs 70 lbs
David and Johnathan each weigh 90 lbs
The answer is 3x+15
You multiply the x and 5 by 3 to get 3x and 15