Given:
s is inversely proportional to t.
When s = 0.5, t = 7.
To find:
The value of s when t=0.8.
Solution:
s is inversely proportional to t.
...(i)
Where, k is the constant of proportionality.
Putting s=0.5 and t=7, we get
Putting k=3.5 in (i), we get
This is the equation of proportionality.
Putting t=0.8, we get
Therefore, the value of s is 4.375 when t=0.8.
The length of pencil A is 5 cm
<em><u>Solution:</u></em>
Let the length of pencil A be "x"
Let the length of pencil B be "y"
Let the length of pencil C be "z"
<em><u>The total length of pencils A, B and C is 29 cm</u></em>
Therefore,
length of pencil A + length of pencil B + length of pencil C = 29
x + y + z = 29 ------------ eqn 1
<em><u>Pencil A is 11 cm shorter then pencil B</u></em>
x = y - 11 ------- eqn 2
<em><u>Pencil B is twice as long a pencil C</u></em>
y = 2z
------ eqn 3
<em><u>Substitute eqn 2 and eqn 3 in eqn 1</u></em>
<em><u>Substitute y = 16 in eqn 2</u></em>
x = 16 - 11
x = 5
Thus length of pencil A is 5 cm
if we look at the equation y = -2x - 1, is already in slope-intercept form, therefore, has a slope of -2.
now, parallel lines have exactly equal slopes, therefore a parallel to that one above, will have also a slope of -2, so we're really looking for a line whose slope is -2 and runs through -1, 7.