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Travka [436]
3 years ago
9

The second term of arithematic proggresions 7. and the sum of the first four termd is 12 find

Mathematics
1 answer:
Elza [17]3 years ago
3 0

Answer:

a) a1=15 first term

b) d=-8 common difference

Step-by-step explanation:

1)a1+d=7

2)a1+a2+a3+a4=12

a1+a1+d+a1+2d+a1+3d=12

4a1+6d=12

2a1+3d=6

We have the system of equations where a1+d=7 and 2a1+3d=6

3a1+3d=21

2a1+3d=6

Subtract the second equation from the first one

a1=15

d=-8

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what is the center of a circle whose equation is x2 + y2 – 12x – 2y + 12 = 0? o (-12,-2) o (-6, -1) o (6, 1) (12, 2)
Leno4ka [110]

Answer:

(6,1)

Step-by-step explanation:

1.) group the x and y terms (and move the constant to the other side)

x²-12x+y²-2y= -12

divide the coeficcents for the terms with just 1 or 1 x variable by 2 and then square it (and add that to both sides)

x²-12x+36+y²-2y+1= -12+36+1

factor

(x-6)²+(y-1)²= 25

the center is therefore (6,1)

7 0
3 years ago
Can y’all help me plz
WITCHER [35]

Answer:

Step-by-step explanation:

I think it is A

7 0
3 years ago
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Which of the following numbers belong to the set of complex numbers AND The set of imaginary numbers? Select all that apply.
Schach [20]
<span>To be both complex and imaginary, the answer would have to include "i" as well as have the form "a + bi". The first example, 3i - 5, fits. This would look to be the only example that does fit. The negative square root of 14 would be imaginary, but not complex.</span>
7 0
3 years ago
write an equation of the line with the same slope as the line given by 5x+2y=8 and as the same y-intercept as 3x-7y=10
Paladinen [302]
The slope of the first equation would be -5/2 because
2y=-5x+8
y=-5x/2+4
The y intercept of the 2nd equation is when x=0, so -7y=10
y=-10/7
The equation of the line would be y=-5x/2-10/7
Or in standard form....
5x/2+y=-10/7
5x+27=-20/7
5 0
3 years ago
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The diagram shows a sector of a circle radius 10 cm. the angle is 135 degrees
Black_prince [1.1K]

Answer:

The perimeter is 43.6 cm

Step-by-step explanation:

In this question, we are tasked with calculating the perimeter of the sector.

Firstly, we define what a sector is. A sector is part of a circle which is is blinded by two radii and an arc. Hence we say a sector contains two radii.

Thus, to calculate the perimeter of the sector, we need the length of the arc added to 2 * length of the radius

Let’s calculate the length of the arc.

Mathematically, this is theta/360 * 2 * pi * r

where theta is the angle subtended at the middle of the circle which is 135 according to the question, and our radius is 10cm

Thus, we have

135/360 * 2 * 22/7 * 10 = 23.57 cm

Adding two radii to this, we have;

23.57 + 2(10)

= 23.57 + 20 = 43.57 = 43.6 cm to 1 decimal place

5 0
3 years ago
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