2.5 kg of potatoes cost £1.40 Work out the cost of 4.25 kg of potatoes. 5.95
1 answer:
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Answer:
(a) (5, -3)
Step-by-step explanation:
The "substitution method" for solving a system of equations requires that you write an expression that can be substituted for a variable in one or more of the other equations in the system.
<h3>Expression to substitute</h3>The given equations are ...
- y = x -8
- 2x +3y = 1
We notice the first equation gives an expression for y. This is exactly what we want to substitute for y in the second equation.
<h3>Substitution</h3>When the expression (x-8) is substituted for y in the second equation, you get ...
2x +3(x -8) = 1
This simplifies to ...
5x -24 = 1
<h3>Solution</h3>This 2-step equation can now be solved in the usual way:
5x = 25 . . . . . . add 24 to isolate the variable term
x = 25/5 = 5 . . . . . divide by the coefficient of x
Note that we now know what the correct answer choice is.
Using the expression for y, we find ...
y = x -8 = 5 -8 = -3
The solution is (x, y) = (5, -3).
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The attached graph confirms this solution.
Answer:
D.
Step-by-step explanation:
We have been given a graph of system of linear equations and we are asked to choose the system of equations representing the given graph.
Upon looking at our graph we can see that our lines intersect at point (0,3). To find the system of equations represented in the graph we will substitute x=0 in our given equations and see which equation gives us an output of 3.
Let us start with 1st option.
A.
Upon substituting x=0 we will get
Since we get 3 on one side of equation and -3 on other side of equation, therefore, option A is not a correct choice.
B.
Upon substituting x=0 we will get,
Since this system of equations intersect at point (0,4), therefore, option B is not a correct choice as well.
C.
Upon substituting x=0 we will get,
Therefore, option C is not a correct choice as well.
D.
Upon substituting x=0 we will get,
Since this system of equations intersect at point (0,3), therefore, option D is the correct choice.