Answer:

Step-by-step explanation:
The cost is given for <em>1 sweatshirt</em>. To find the cost of 15 sweatshirts, we need to multiply the expression by 15. Let's do this:

This is the expression that represents the cost of 15 sweatshirts.
Answer:
The correct answer is;
ΔANT ≅ ΔFLE by the SIde-Side-Side (SSS) rule of congruency
Step-by-step explanation:
The given information are;
Segment TN is congruent ts segment EL
Segment TA is congruent ts segment EF
Segment AN is congruent ts segment FL
Therefore, triangle ΔANT is congruent to ΔFLE by the Side-Side-Side (SSS) rule of congruency
One of the rule used to serve as proof that two or more triangles are congruent, is the Side-Side-Side (SSS) rule of congruency. The Side-Side-Side rule of congruency states that if the dimensions of the three sides of one triangle are equal to the dimensions of the three sides of another triangle, the two triangles are congruent.
Therefore, the correct option is ΔANT ≅ ΔFLE by the Side-Side-Side (SSS) rule of congruency
No.
Perpendicular lines are lines that intersect at a 90° angle.
If two lines are perpendicular, they create four 90° angles.
However, for two lines to intersect, they do not necessarily have to intersect at a 90° angle.
<em>All roses are flowers, but not all flowers are roses.</em>
<em>All perpendicular lines are intersecting lines, but not all intersecting lines are perpendicular.</em>
Answer:
Step-by-step explanation:
Let 
Subbing in:

a = 9, b = -2, c = -7
The product of a and c is the aboslute value of -63, so a*c = 63. We need 2 factors of 63 that will add to give us -2. The factors of 63 are {1, 63}, (3, 21}, {7, 9}. It looks like the combination of -9 and +7 will work because -9 + 7 = -2. Plug in accordingly:

Group together in groups of 2:

Now factor out what's common within each set of parenthesis:

We know this combination "works" because the terms inside the parenthesis are identical. We can now factor those out and what's left goes together in another set of parenthesis:

Remember that 
so we sub back in and continue to factor. This was originally a fourth degree polynomial; that means we have 4 solutions.

The first two solutions are found withing the first set of parenthesis and the second two are found in other set of parenthesis. Factoring
gives us that x = 1 and -1. The other set is a bit more tricky. If
then
and

You cannot take the square root of a negative number without allowing for the imaginary component, i, so we do that:
±
which will simplify down to
±
Those are the 4 solutions to the quartic equation.