Answer:
The first equation should be multiplied by 9 and the second equation by −4
Step-by-step explanation:
Given the simultaneous equation
First Equation: 5x − 4y = 28
Second equation: 3x - 9y = 30
In order to eliminate y, we must make the coefficient of x in both expression to be equal.
To do that the first equation should be multiplied by 9 (negative value of the coefficient of y in equation 2)and the second equation by -4( (coefficient of y in equation 1)
30 x 2 = 60 min running
30 - 10= 20 min biking
30+60+20=110 min, or an hour and 50 minutes
60
D>0, there are 2 distinct real roots
Explanation:
3x2+6x−2=0
a=3,b=6,c=−2
The formula for discriminant is b2−4acSubstitute the given values.
b2−4ac
(6)2−4(3)(−2)
=60
therefore, D>0, there are 2 distinct real roots
You didn't include the options, so whichever one looks like x=(12.53+11.86)3.19 or something similar. You need to add the amount of gallons he bought, then multiply them by the cost per gallon, which will most likely be set equal to a variable.
I learned this so many times but I forgot how to do it exactly.
But looking at this, you can already determine that y is equal to -3 so couldn't you use that as an answer.
