If fx = 5x - what is the value of f(5)?

Jenny and Natalie are selling cheesecakes for a school fundraiser. Customers can buy chocolate cakes and vanilla cakes. Jenny so

IrinaVladis [17]

The cost of 1 chocolate cake is $ 6 and cost of 1 vanilla cake is $ 7

Solution:

Let "c" be the cost of 1 chocolate cake

Let "v" be the cost of 1 vanilla cake

Jenny sold 14 chocolate cakes and 5 vanilla cakes for 119 dollars

Therefore, we can frame a equation as:

14 x cost of 1 chocolate cake + 5 x cost of 1 vanilla cake = 119

$14 \times c + 5 \times v=119$

14c + 5v = 119 ------- eqn 1

Natalie sold 10 chocolate cakes and 10 vanilla cakes for 130 dollars

Therefore, we can frame a equation as:

10 x cost of 1 chocolate cake + 10 x cost of 1 vanilla cake = 130

$10 \times c + 10 \times v = 130$

10c + 10v = 130 -------- eqn 2

Let us solve eqn 1 and eqn 2

Multiply eqn 1 by 2

28c + 10v = 238 ------ eqn 3

Subtract eqn 2 from eqn 3

28c + 10v = 238

10c + 10v = 130

( - ) --------------------------

18c = 108

c = 6

Substitute c = 6 in eqn 1

14(6) + 5v = 119

84 + 5v = 119

5v = 119 - 84

5v = 35

v = 7

Thus cost of 1 chocolate cake is $ 6 and cost of 1 vanilla cake is $ 7

8 0

2 years ago

Consider the function f ( x ) = − 2 x 3 + 27 x 2 − 108 x + 9 . For this function there are three important open intervals: ( − [

Darya [45]

Answer:

A=3 and B=6

Step-by-step explanation:

Increasing and Decreasing Intervals of Functions

Given f(x) as a real function and f'(x) its first derivative.

If f'(a)>0 the function is increasing in x=a

If f'(a)<0 the function is decreasing in x=a

If f'(a)=0 the function has a critical point in x=a

As we can see, the critical points may define open intervals where the function has different behaviors.

We have

$f ( x ) = - 2 x^3 + 27 x^2 - 108 x + 9$

Computing the first derivative:

$f' ( x ) = - 6 x^3 + 54 x - 108$

We find the critical points equating f'(x) to zero

$- 6 x^3 + 54 x - 108=0$

Simplifying by -6

$x^2 -9 x +18=0$

We get the critical points

$x=3,\ x=6$

They define the following intervals

$(-\infty,3),\ (3,6),\ (6,+\infty)$

Thus A=3 and B=6

3 0

3 years ago

I WILL GIVE BRAINLIST HELP PLEASE

il63 [147K]

Answer:

area- 55 perimeter - 24

Step-by-step explanation:

small rectangle =

5- 3 = 2

2 × 3 = 6cm²

big rectangle =

4 + 3 = 7

7 × 7 = 49cm²

All together

6 + 49 = 55cm²

Perimeter -

7 0

3 years ago

123÷6×7[(654+2)×(12÷3)]

melomori [17]

Answer:

Step-by-step explanation:

123/6 x 7[(654 + 2) x (12/3)].....do whats in parenthesis first

123/6 x 7[656 x 4] ......do whats in brackets

123/6 x 7(2624) ....do multiplication/division from left to right, whichever comes first

20.5 x 18,368 =

376544 <===

8 0

3 years ago

Read 2 more answers

SOMEONE PLS HELP WILL GIVE BRAINLIEST ANSWER IF CORRECT

Mamont248 [21]

Complementary angles add up to 90°
and supplementary angles add up to 180°

Add the two angles together
82+98=180
So the measure of these two angles are supplementary

6 0

3 years ago