91影视

Evaluate the expression $鈭�25\left(鈭�5\right)$.

For which triangle is the height not $4\frac{1}{2}b$where $b$is the length of the base?

Find the value of n in each equation. Then name the property that is used.

$1=2n$

Solve each equation or formula for the variable indicated.

$14w+15x=y鈭�21w$,for$w$

Write and solve the equation for the sentence 鈥淣egative 117 is nine times a number鈥� What is the number?

Write and solve the equation for the sentence 鈥淭welve is one fifth a number鈥� What is the number?

Solve each equation or formula for the variable indicated.

$m=\frac{2}{5}y+n$,for$y$

Evaluate each expression.

$5+3{\left(4\right)}^2$

CHALLENGE Determine whether each sentence is sometimes, always, or never true. Explain your reasoning.

a.$x+x=x$

b.$x+0=x$

REASONING Determine the value for each statement below.

a. If $x鈭�7=14$, what is the value of $x鈭�2$?

b. If $t+8=鈭�12$, what is the value of $t+1$?