If the ratios form a proportion, the ratios will be equal. first we'll simplify the ratios:
14/21
divide top and bottom by 7
2/3
26/39
divide top and bottom by 13
2/3
ss you can see now, the ratios are indeed equal, so they do form a proportion
Answer:
The brother sold 33 subscriptions
The sister sold 19 subscriptions
Step-by-step explanation:
Let's represent the number is subscription as:
For the brother = a
For the sister = b
a + b =52
The sister sold 5 fewer than twice the number of her brother sold .
a= 2b - 5
Hence, substitute 2b - 5 for a I. The above equation.
a + b =52
2b - 5 + b = 52
3b = 52 + 5
3b = 57
b = 57/3
b = 19
a + b = 52
a + 19 = 52
a = 52 - 19
a = 33
Therefore,
the brother sold 33 subscriptions
the sister sold 19 subscriptions
The sale price would be 24.64
Answer:
y = x² + 7x + 4
Step-by-step explanation:
<u>First option</u>
System of equations:
y = x² + x – 4
y = x – 5
Replacing:
x - 5 = x² + x – 4
0 = x² + x – 4 - x + 5
0 = x² + 1
Discriminant:
b²-4*a*c
0²-4*1*1
-4 < 0 then the equation has no real roots
<u>Second option</u>
System of equations:
y = x² + 2x – 1
y = x – 5
Replacing:
x - 5 = x² + 2x – 1
0 = x² + 2x - 1 - x + 5
0 = x² + x + 4
Discriminant:
b²-4*a*c
1²-4*1*4
-15 < 0 then the equation has no real roots
<u>Third option</u>
System of equations:
y = x² + 6x + 9
y = x – 5
Replacing:
x - 5 = x² + 6x + 9
0 = x² + 6x + 9 - x + 5
0 = x² + 5x + 4
Discriminant:
b²-4*a*c
5²-4*1*4
9 > 0 then the equation has two different real roots
<u>Fourth option</u>
System of equations:
y = x² + 7x + 4
y = x – 5
Replacing:
x - 5 = x² + 7x + 4
0 = x² + 7x + 4 - x + 5
0 = x² + 6x + 9
Discriminant:
b²-4*a*c
6²-4*1*9
0 then the equation has one real root
No 72 is not a perfect square
