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4 years ago

Giselle works as a carpenter and as a blacksmith.

Mathematics

1 answer:

Usimov [2.4K]4 years ago

8 0

Answer:

34.5 hours as carpenter or 27.6 hours for blacksmith (Not sure about this sorry)

Step-by-step explanation:

690 ÷ 20 and 690 ÷ 25

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I need to figure out how to solve this and the answer

Dominik [7]

Answer:

C=13

Step-by-step explanation:

Ok, so those to angles are going to equal 90*.

First, you wan to setup your equation,

(2c-4) + (5c+3) = 90

now you want to add the angles

7c -1 = 90

isolate the variable .

Add 1 to both sides

7c=91

Now divide 7 from both sides

c=13.

To check our work we will plug in for C.

2(13)-4 + 5(13)+3=90

26 - 4 + 65 + 3=90

90=90

7 0

3 years ago

I need help :( Please and thank you

Nataly [62]

Cross multiply
17x9 = 153
U x 11 = 11u
Set equal to eachother
153=11u
Divide 11 on both sides
153/11=11u/11
13.90909090 = u
U = 13.9

5 0

3 years ago

If f(x) = 3 ^ x - 4 what is f(- 2) ?

Karolina [17]

Answer:

-35/9

Step-by-step explanation:

(3^-2)-4

1/9-4

-35/9

8 0

3 years ago

Set up but do not solve for the appropriate particular solution yp for the differential equation y′′+4y=5xcos(2x) using the Meth

taurus [48]

Answer:

So, solution of the differential equation is

$y(t)=-\frac{5x^2}{4}\cot 2x\cdot \cos 2x+c_1e^{-2it}+c_2e^{2it}\\$

Step-by-step explanation:

We have the given differential equation: y′′+4y=5xcos(2x)

We use the Method of Undetermined Coefficients.

We first solve the homogeneous differential equation y′′+4y=0.

$y''+4y=0\\\\r^2+4=0\\\\r=\pm2i\\\\$

It is a homogeneous solution:

$y_h(t)=c_1e^{-2i t}+c_2e^{2i t}$

Now, we finding a particular solution.

$y_p(t)=A5x\cos 2x\\\\y'_p(t)=A5\cos 2x-A10x\sin 2x\\\\y''_p(t)=-A20\sin 2x-A20x\cos 2x\\\\\\\implies y''+4y=5x\cos 2x\\\\-A20\sin 2x-A20x\cos 2x+4\cdot A5x\cos 2x=5x\cos 2x\\\\-A20\sin 2x=5x\cos 2x\\\\A=-\frac{x}{4} \cot 2x\\$

we get

$y_p(t)=A5\cos 2x\\\\y_p(t)=-\frac{5x^2}{4}\cot 2x\cdot \cos 2x\\\\\\y(t)=y_p(t)+y_h(t)\\\\y(t)=-\frac{5x^2}{4}\cot 2x\cdot \cos 2x+c_1e^{-2it}+c_2e^{2it}\\$