Answer:
3.2seconds
Step-by-step explanation:
Step one:
Robert run the 100 meter dash in 13.5 seconds
We are told that he later run same distance in 10.3 seconds
Required.
The time difference in the first dash and the second
Step two:
The first dash took 13.5 seconds
the second took 10.3 seconds
the difference = 13.5-10.3= 3.2seconds
Firstly you have to reduce the 4 variables to a double system of equation with only 2 variables.
Let's say, first we have to eliminate Z:
Take 1st & 3rd equation & multiply each term of the 1st by (- 1). One done you add up the 1st & the 3rd & you will get:
5W - 4x + 2y = - 18
Follow the same methodology to find another equation without z. Once done you will have a system of 2 equation with 2 variable easy to solve,
At the end you will find:
w = -3
x = -2
y = -1
z = 3
Answer:
Step-by-step explanation:
3x + 3
6 + 2x
3x + 2x = 5x
3 + 6 = 9
5x + 9