Step-by-step explanation:
By substituting x = 0.4 in equation 7 + (-3x^2)
= 7 - 3 (0.4)^2
First solving o.4^2 as per the rule of BODMAS
= 7- 3 (0.16)
Now multiplying -3 with 0.16
= 7 - 0.48
= 6.52 THIS IS THE ANSWER
Hiya. I'm going to rewrite the second equation.
By subtracting 5x by both sides, I'll be able to have y by itself:
-y=-5x+13
I'm going to then divide both sides by -1 to get:
y=5x-13.
Then, I'm going to plug that equation into the first equation
3x+2(5x-13)=39
Factor:
3x+10x-26=39
Combine like terms:
13x=65
Divide both sides by 13 to get x by itself to get x=5
Plug this back into the equation of y=5x-13
y=5(5)-13 to get y=12
Answer:
He pays to the cab driver for 25 miles.
Step-by-step explanation:
Consider the provided information.
Let us consider he walks x miles at the rate of 4 miles per hour.
As we know 
Therefore, time taken is: 
He get a taxi for (31-x) miles at the rate of 50 miles per hour.
Therefore, time taken is: 
It took 2 hours after he started.
That means the sum of time take is 2 hours.
Hence he walk 6 miles and he get a taxi for 31-6=25 miles.
He pays to the cab driver for 25 miles.
Answer:
x=8
Step-by-step explanation:
