X3-7x=6x-12
x3-7x-6x+12=0
x3-13x+12=0
(x-1)(x2+x-12)=0
Calculate delta of the second bracket:
delta = 1+4*12=49
sqrt(delta)=sqrt(49)=7
x_1=(-1-7)/2=-4
x_2=(-1+7)/2=3
(x-1)(x+4)(x-3)=0
Answear:
Roots: x=1, x=-4, x=3.
Answer:
Hello. The answer is 250.
Step-by-step explanation:
The explanation takes alot of time
The two important tips are
Sum of the interior angles of triangle is 180
And for those which have 4 sides are 360
Call the notebooks x, and the pencils y.
<span>3x + 4y = $8.50 and 5x + 8y = $14.50 </span>
<span>Then just solve as simultaneous equations: </span>
<span>3x + 4y = $8.50 </span>
<span>5x + 8y = $14.50 </span>
<span>5(3x + 4y = 8.5) </span>
<span>3(5x + 8y = 14.5) </span>
<span>15x + 20y = 42.5 </span>
<span>15x + 24y = 43.5 </span>
<span>Think: DASS (Different Add, Similar Subtract). 15x appears in both equations so subtract one equation from the other. Eassier to subtract (15x + 20y = 42.5) from (15x + 24y = 43.5) </span>
<span>(15x + 24y = 43.5) - (15x + 20y = 42.5) = (4y = 1) which means y = 0.25. </span>
<span>Then substitue into equation : </span>
<span>15x + 20y = 42.5 </span>
<span>15x + 5 + 42.5 </span>
<span>15x = 42.5 - 5 = 37.5 </span>
<span>15x = 37.5 </span>
<span>x = 2.5 </span>
<span>15x + 24y = 43.5 </span>
<span>15(2.5) + 24(0.25) </span>
<span>37.5 + 6 = 43.5 </span>
<span>So x (notebooks) are 2.5 ($2.50) each and y (pencils) are 0.25 ($0.25) each.</span>
Filling in the boxes:
Top row outside box: 3c and 8
Second row outside box: - or -1
Inside box: -3c and -8
Expanded: -3c - 8
Answer:
1. Interest: 15%
Amount owed: $500
2. Interest: 6%
Amount owed: $1,500
3. Interest: 18%
Amount owed: $12,500
4. Interest: 6%
amount owed: $5,000
Step-by-step explanation:
