Answer:
t α 1 /r ; t = k/r
Step-by-step explanation:
Given that :
Time taken, t varies inverse as rate, r
MATHEMATICALLY,
t α 1 /r
Hence,
t = k/r ;
Where, k is the proportionality constant
Hence, the situation could be expressed as :
t = k/r OR
t α 1 /r
Divide 20 by 4=5
then 5 by 7=5/7
k=5/7
Answer:
A=5
Step-by-step explanation:
Hence the value of a and b are 5
Substitute 2x + 3 for y
4x - 2(2x+3) = -6
4x - 4x - 6 = -6
-6 = -6
true, so the solution is all real numbers
Answer:
(1,-1)
Step-by-step explanation:
We can solve the system by using substitution.
In order to do this we must make x the subject in the first equation.
We can do this by simply subtract 2y from both sides
x + 2y = -1
subtract 2y from both sides
x + 2y - 2y = -1 - 2y
simplify
x = -2y - 1
now that we have made x the subject in one of the equations we can plug in (or substitute) the value of x into the other equation
2x – 3y = 5
x = -2y - 1
2(-2y - 1) - 3y = 5
We can then solve for y
2(-2y - 1) - 3y = 5
Distribute the 2
-4y - 2 - 3y = 5
combine like terms -4y + -3y
-7y - 2 = 5
add 2 to both sides
-7y = 7
divide both sides by -7
y = -1
Now that we have found the value of y we can plug in the value of y into one of the equations and solve for x
x + 2y = -1
y = - 1
x + 2(-1) = -1
multiply 2 and -1
x + -2 = -1
add 2 to both sides
x = 1
So we have found that x = 1 and y = -1 therefore the solution to the system of equations is (1,-1)