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3 years ago

PLZZZ HELPPPPPPP LAST QUESTIONS LAST CHANCE FOR POINTSSSS REWARD BRAINLIESTT

Mathematics

2 answers:

vlada-n [284]3 years ago

8 0

Answer:

17)x=12, -7

18)x=+2, -2

19)(2x-5)(3x+1)

20)3(5x+4)(x-2)

Step-by-step explanation:

17) (x-12)(x+7)=0

x=12, -7

18)3x^2-12=0

3x^2=12

x^2=4

x=+2, -2

19)(ax+b)(cx+d)

Ax^2+Bx+C

A=6, B=-13, C=-5

ac=6

ad+bc=-13

bd=-5

a=2

b=-5

c=3

d=1

(2x-5)(3x+1)

20)3(5x^2-6x-8)

=3(5x+4)(x-2)

Hope I helped! And also, is this really college math? I'm in middle school and I know how to do it!

Can you give me brainliest, since I did all of them?

Nimfa-mama [501]3 years ago

3 0

Answer:

question 19

(2x-5)(3x+1)

Step-by-step explanation:

question 19

6x^2-13x-5

6x^2 coefficient = 6

-13x coeddicient = -13

-5 is constant

multiply coefficient of first term by the constant

i.e. 6*-5= -30

get 2 factors of -30 whoose sum equals -13

-15 +2 = -13

rewrite to have

6x^2-15x+2x-5

3x(2x-5) the firs term

1(2x-5)

add up,

(3x+1)(2x-5)

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babymother [125]

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4 0

3 years ago

The lengths of the three sides of a triangle (not necessarily a right triangle) are 3.16 meters, 8.25 meters and 10.4 meters. wh

Dafna1 [17]

For non-right triangles you must use the "Law of Cosines" and then, the "Law of Sines" to solve this.

a= 8.25m
b= 10.4m
c= 3.16m
∠A= UNKNOWN
∠B= UNKNOWN
∠C=UNKNOWN

Law of Cosines:
c²= a²+b²-2abCos(C)
(3.16)²= (8.25)²+(10.4)²- 2(8.25)(10.4)(cos(C))
9.9856 = 68.0625 + (108.16) - (171.6)(cos(C)
9.9856 = 176.2225- 171.6 cos C
-166.2369= - (171.6(cosC))
cosC= 0.968746503
Take the inverse cosine of that to get the measure of angle C
∠C= 15.95813246°

Now Use law of sines to find ∠B:
$\frac{10.4}{Sin(B)} = \frac{3.16}{sin(15.96)}$
$\frac{10.4}{Sin(B)} =12.73922$
$10.4 =12.73922115(sinB)$
$sinB= 0.816276439$
(take the inverse sine to get the measure of ∠B)
∠B= 60.8040992°


Answer:
The angle measures approximately 60.80°.