Let n represent the amount Colin earned on Sunday.

On Sat. he earned n/2; on Sun. he earned n; and on Friday he earned (1/2)(n/2).

Then n/2 + n + n/4 = $70

Mult. all terms by 4 to eliminate fractions:

2n + 4n + n = $280

7n = $280 => n = $40

Colin earned n/2, or $20, on Saturday; n, or $40, on Sunday; and n/4, or $10, on Friday.

Note that $20 and $40 and $10 add up to $70, as they must.

4 0

3 years ago

The points A-1,-9) and K(5,1) are endpoints of a diameter of circle 5. Which equation represents circle S?

Lilit [14]

Answer:

Step-by-step explanation:

if (x1,y1) and (x2,y2) are the extremities of diameter,then eq. of circle is

(x-x1)(x-x2)+(y-y1)(y-y2)=0

reqd. eq. is (x+1)(x-5)+(y+9)(y-1)=0

$x^{2} +x-5x-5+y^2+9y-y-9=0\\x^{2} -4x+y^2+8y-14=0\\compare with x^2+y^2+2gx+2fy+c=0\\center (-g,-f) \\radius r=\sqrt{g^2+f^2-c}$

center is (2,-4)

r=√(2²+(-4)²-(-14))

=√(4+16+14)

=√(34)

eq. of circle is (x-2)²+(y+4)²=34

(x²-4x)+(y²+8y)=14

(x²-4x+4)+(y²+8y+16)=14+4+16

(x-2)²+(y+4)²=34

4 0

3 years ago

The measure of ∠1 =<br><br> 188<br> 172<br> 94

yanalaym [24]

Answer: Third option is correct.

Step-by-step explanation:

Since we have given that

There is a cyclic quadrilateral.

As we know that "Sum of opposite angles in a cyclic quadrilateral is supplementary.":

so, it becomes,

$86^\circ+\angle 1=180^\circ\\\\\angle 1=180^\circ-86^\circ\\\\\angle 1=94^\circ$

Hence, the measure of ∠1 = 94°

Therefore, Third option is correct.

4 0

3 years ago