Question

read each problem carefully and sold as required and answer the questions that ffollow​

Answer 1

Answer:

Answer 1.

The two equations are :-

$\bf \:x + y = 15$

$\bf \:20x + 25y = 340$

where, x is number of white chocolates and y be number of dark chocolates.

Answer :- 2.

There are four methods to solve such equations :-

1. Substitution Method
2. Elimination Method
3. Cross Multiplication Method
4. Graphical Method

We prefer Substitution Method.

• The method of solving "by substitution" works by solving one of the equations (you choose which one) for one of the variables (you choose which one), and then plugging this back into the other equation, "substituting" for the chosen variable and solving for the other. Then you back-solve for the first variable.

Answer :- 3.

Janie has 7 white chocolates and 8 dark chocolates.

Step-by-step explanation:

Let number of white chocolates be 'x' and number of datk chocolates be 'y'.

★ Case :- 1.

Janie had total 15 chocolates.

$\bf\implies \:x + y = 15$

$\bf\implies \:y = 15 - x......(1)$

★ Case :- 2.

The cost of white chocolate is php 20 and cost of dark chocolate is php 25. She had chocolates of php 340.

$\bf\implies \:20x + 25y = 340$

Substituting the value of y evaluated in (1), we get

$\bf\implies \:20x + 25(15 - x) = 340$

$\bf\implies \:20x + 375 - 25x = 340$

$\bf\implies \:375 - 5x = 340$

$\bf\implies \:5x = 35$

$\bf\implies \:x = 7$

Put x = 7, in equation (1), we get

$\bf\implies \:y = 15 - 7 = 8$

Answer 2

Step-by-step explanation:

1)X+Y=15 and 4X+5Y=68

2)Elimination method

Because if we use this method then we eliminate one variable and find easily another variable.

3)No. of white chocolates=7

No. of dark chocolates=8