Solve using the substitution method: 6x + y =15 4x + 3y = 31

Please help me answer this Explain you’re answer Will give braisnlt

lions [1.4K]

B the answer is B - hope this helps you out

7 0

3 years ago

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If f(x)= 3x squares +1 and g(x) =1-x what is the value of (f-g)(2)

ZanzabumX [31]

Answer: (f-g)(2)=14

Step-by-step explanation:

(f – g) (-2) means the same as subtracting f(2) and g(2). Since we are given f(x) and g(x), we can use them to solve. There are two ways to solve. One is to find f(2) and g(2), and then subtract them. Another way is to do (f-g)(x), then plug in x=2. I will show both methods.

Method 1

f(2)=3(2)²+1 [exponent]

f(2)=3(4)+1 [multiply]

f(2)=12+1 [add]

f(2)=13

g(2)=1-(2) [subtract]

g(2)=-1

(f-g)(2)=13-(-1) [subtract f(2) and g(2)]

(f-g)(2)=14

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Method 2

(f-g)(x)=3x²+1-(1-x) [distribute -1]

(f-g)(x)=3x²+1-1+x [combine like terms]

(f-g)(x)=3x²+x

(f-g)(2)=3(2)²+2 [plug in x=2, exponent]

(f-g)(2)=3(4)+2 [multiply]

(f-g)(2)=12+2 [add]

(f-g)(2)=14

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Now, we know that (f-g)(2)=14. We confirmed this with both methods.

8 0

4 years ago

In ΔBCD, the measure of ∠D=90°, the measure of ∠C=77°, and CD = 41 feet. Find the length of BC to the nearest foot.

OLga [1]

Answer:

182 ft

Step-by-step explanation:

When you are not given a diagram, always draw one for yourself (see diagram).

When you have a right triangle (triangle with 90° angle), you can use the trigonometry ratios, You can remember them using SohCahToa. It is read like this:

sinθ = opposite/hypotenuse Soh

cosθ = adjacent/hypotenuse Cah

tanθ = opposite/adjacent Toa

"θ" means the angle of reference (the angle you are talking about).

We are looking for the length of BC, which is the hypotenuse. I labelled it "d" (lowercase D) because it is opposite to ∠D.

We know ∠C = 77°. This will be our angle of reference (replace θ).

The side we know is DC, also known as "b" (lowercase B) because it's opposite to ∠B. "b" is the adjacent side when θ = C because "b" is touching ∠C.

Take the general trig. formula that has hypotenuse and adjacent: (cosine ratio)

cosθ = adjacent/hypotenuse

Substitute the variables specific for this problem.

cosC = b/d

Substitute the values you know.

cos77° = (41 ft) / d

Isolate "d" to the left side

dcos77° = $d*\frac{41ft}{d}$ Multiply both sides by "d"

dcos77° = 41 ft

dcos77° / cos77° = 41 ft / cos77° Divide both sides by cos77°

d = 41 ft / cos77° Input into calculator

d = 182.261874....... ft Unrounded answer

d ≈ 182 ft Rounded to nearest foot (whole number)

Remember d = BC. It's often easier to use one letter for calculations.

Therefore the length of BC is about 182 feet.

8 0

3 years ago

Ken has already baked 4 pies and he can bake 1 pie with each additional cup of sugar he buys. With 31 additional cups of sugar,

Bumek [7]

Answer: 35 pies

Step-by-step explanation:

Ken can bake 1 pie with each additional cup of sugar he buys. 1 pie =1 cup

4 + x = y

Where;

x= additional pies

y= total pies

If 1 cup= 1 pie; then 31 cups =

31 cup × 1 pie/1 cup = x

:. x= 31 pies

y= x + 4

y= 31+4 = 35

6 0

3 years ago

What is the range of 17, 12, 28, 21, 14, 74, 32, 14, 25, 23

natita [175]

Answer:

it's 22 I hope you got it right if not then i'm sorry

8 0

3 years ago

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