Solve using substitution. 9x + 4y = –7 y = –4 (_____, _____)

Identify Equations and Method: Identify the given equations and the substitution method to be used. We have two equations: 9x + 4y = –7 (Equation 1) y = –4 (Equation 2) We will substitute the value of y from Equation 2 into Equation 1 to find the value of x.Substitute y into Equation 1: Substitute y = –4 into Equation 1. Substituting y = –4 into 9x + 4y = –7 gives us: 9x + 4(-4) = –7Simplify and Solve for x: Simplify the equation and solve for x. 9x - 16 = –7 Now, add 16 to both sides of the equation: 9x - 16 + 16 = –7 + 16 9x = 9 Next, divide both sides by 9 to find x: 9x / 9 = 9 / 9 x = 1Write Ordered Pair Solution: Write the solution as an ordered pair. Since we have found x = 1 and we know y = –4, the solution to the system of equations is (1, –4).

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Solve using substitution. $\newline$ $9x + 4y = -7$ $\newline$ $y = -4$ $\newline$ (_, _)

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Precalculus

Solve a system of equations using substitution

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Q. Solve using substitution.

\newline

9x + 4y = -7

\newline

y = -4

\newline

(_____, _____)

Identify Equations and Method: Identify the given equations and the substitution method to be used. $\newline$ We have two equations: $\newline$ $9x + 4y = -7$ (Equation $1$ ) $\newline$ $y = -4$ (Equation $2$ ) $\newline$ We will substitute the value of $y$ from Equation $2$ into Equation $1$ to find the value of $x$ .
Substitute $y$ into Equation $1$ : Substitute $y = -4$ into Equation $1$ . $\newline$ Substituting $y = -4$ into $9x + 4y = -7$ gives us: $\newline$ $9x + 4(-4) = -7$
Simplify and Solve for x: Simplify the equation and solve for x. $\newline$ $9x - 16 = -7$ $\newline$ Now, add $16$ to both sides of the equation: $\newline$ $9x - 16 + 16 = -7 + 16$ $\newline$ $9x = 9$ $\newline$ Next, divide both sides by $9$ to find x: $\newline$ $\frac{9x}{9} = \frac{9}{9}$ $\newline$ $x = 1$
Write Ordered Pair Solution: Write the solution as an ordered pair. $\newline$ Since we have found $x = 1$ and we know $y = -4$ , the solution to the system of equations is $(1, -4)$ .