Long Answer TypeAftab tells his daughter, 'Seven years ago, I was seven times as old as you were then. Also, three years from now, I shall be three times as old as you will be'. (Isn’t this interesting?) Represent this situation algebraically and graphically.
(i) 10 students of Class X took part in Mathematics quiz. If the number of girls is 4 more than the number of boys, find the number of boys and girls who took part in the quiz.
(i) Let the number of boys be x and number of girls be y.
Case I. x + y = 10 ...(i)
Case II. y = x + 4
⇒ x - y = -4 ...(ii)
We have, x + y = 10
⇒ x = 10 - y
Thus, we have following table :
Fig. 3.4.
We have, x - y = -4
⇒ x = y - 4
Thus we have following table :
When we plot the graph of the given equation, we find that both the lines intersect at me point (3, 7). So.r = 3,y = 7 is the required solution of the pair of linear equation.
Hence, the number of boys be 3 and the number of girls be 7, who took part in quiz.
Short Answer Type
and without drawing them, find out whether the lines representing the following pairs of linear equations intersect at a point, are parallel or coincide.
and without drawing them, find out whether the lines representing the following pairs of linear equations intersect at a point, are parallel or coincide.
and without drawing them, find out whether the lines representing the following pairs of linear equations intersect at a point, are parallel or coincide.
find out whether the following pair of linear equations are consistent, or inconsistent.
find out whether the following pair of linear equations are consistent, or inconsistent.
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