Expand and simlify: a)-2{3a-4{a-(2+a)]} b)5{3c-[d-2(c+d)]}

a) -2 [ 3a-4(a-2-a) ]

= -2[ 3a - 4×(-2) ]

= -2( 3a + 8 )

= -6a-16

b) 5 [ 3c- ( d-2c-2d ) ]

= 5 [ 3c - (-d -2c ) ]

= 5 ( 3c + d + 2c )

= 5 ( 5c + d )

= 25c + 5d

the answer is b.

step-by-step explanation:

by the trigonometric ratio tangent, tangent equals opposite divided by adjacent.

therefore, tan(50) equals ac/3

multiply each side by 3 to get: ac=3tan(50)

the answer is b.

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116