Distinguishing Between Expressions and Equations(TEKS.Math.6.7.B)
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Texas 6th Grade Math › Distinguishing Between Expressions and Equations(TEKS.Math.6.7.B)
Which statement correctly compares $3x+5$ and $3x+5=14$?
Both are equations because they both have numbers and variables.
Both are expressions because they both have operations.
$3x+5$ is an equation you can solve; $3x+5=14$ is just a phrase.
$3x+5$ is an expression (no equal sign), and $3x+5=14$ is an equation (has an equal sign).
Explanation
Expressions are mathematical phrases without equal or inequality signs. Equations are mathematical sentences that include an equal sign. So $3x+5$ is an expression and $3x+5=14$ is an equation.
Which of these is an expression (not an equation or inequality)?
$7n-4$
$\frac{p}{3}+9\le 20$
$2(x+5)=18$
$k>12$
Explanation
An expression is a mathematical phrase with no equal or inequality sign. $7n-4$ is an expression. The others are a inequality ($\le$ or $>$) or an equation (equal sign).
Which choice lists an equation, an expression, and an inequality in that order?
\$4(a+2)$, $7m-1=20$, $w<9$
$3k>5$, $9-2n$, $t+4=11$
$2x+5=17$, $5y-3$, $q\ge 8$
$h\le 4$, $6(z-1)$, $r^2+7=20$
Explanation
Equations have an equal sign, expressions have no equal or inequality sign, and inequalities have inequality signs. In C: $2x+5=17$ (equation), $5y-3$ (expression), $q\ge 8$ (inequality).
What is the difference between $2y-7>10$ and $2y-7=10$?
Both are inequalities; the first uses greater than, the second uses equal to.
$2y-7>10$ is an inequality (uses an inequality sign), and $2y-7=10$ is an equation (uses an equal sign).
$2y-7>10$ is an expression, and $2y-7=10$ is an inequality.
Both are expressions because they include variables and operations.
Explanation
Inequalities are mathematical sentences with inequality signs (like greater than). Equations are mathematical sentences with an equal sign. Expressions have neither sign.