Solve the simultaneous equation using substitution method:4x = y + 7and 3x + 4y + 9 = 0
I dont understand how to solve it
By substitution:
form 4x = y + 7 ---> y = 4x - 7
into the 2nd:
3x + 4(4x-7) + 9 = 0
19x = 19
x = 1
then y = 4(1) - 7 = -3
Standard form:
4x-y = 7.
3x+4y = -9.
Multiply first Eq by 4 and add the Eqs.:
16x-4y = 28
3x+4y = -9
sum: 19x = 19
X = 1.
In Eq2, replace x with 1 and solve for y:
3*1+4y = -9
8y+42=7and6y-82=41
What is the correct answer
5a-ab=-1 and 3a+4b=-2
To solve the given system of equations using the substitution method, we need to solve one equation for one variable and substitute it into the other equation. Let's solve the first equation for y:
4x = y + 7.
Rearranging the equation, we get:
y = 4x - 7.
Now, substitute this value of y into the second equation:
3x + 4y + 9 = 0.
Replace y with 4x - 7:
3x + 4(4x - 7) + 9 = 0.
Distribute the 4:
3x + 16x - 28 + 9 = 0.
Combine like terms:
19x - 19 = 0.
Add 19 to both sides:
19x = 19.
Divide both sides by 19:
x = 1.
Now, substitute this value of x back into the first equation to find y:
4(1) = y + 7.
4 = y + 7.
Subtract 7 from both sides:
-3 = y.
So, the solution to the simultaneous equations is x = 1 and y = -3.