3x=4x5+10
x=?
10
3(2x2-3)
6x2-9
(4x+5y)-(-5x+3y)
(9x+2y)
2x(3X2-2)+(x-3)
6x3-3x-3
Ali buys two pencils. Each pencil costs the same. If he pays $6 in total, how much does one pencil cost?
Each pencil costs $3.
2/5=x/10
x=4
a(a3-a2+2a)
a4-a3+2a2
(x2)3
x6
2x(x-5)+3(x2+2x)
5x2-4x
Sarah is 3 years older than her brother. Together, they are 21 years old. How old is Sarah?
Brother = 9 years, Sarah = 12 years
x-3/2=2x+1/3
x=-11
5y(-4y-7)
-20y2-35y
x3y/xy
x2
5x(3x+2)-2y(y2-4)
15x2+10x-2y3+8y
A rectangle has a length of (4x) and a width of (x). If the perimeter is 30 cm, what is the value of x?
Width = 3 cm, Length = 12 cm
3x+y=-7
y=x+5
X=-3 y=2
2x(3x-3)
(-3x2)4
81x8
3x(2x+3)-2x(x2-3)
-2x3+6x2+15x
John earns $4 per hour cutting grass. His sister earns $10 for helping their neighbour, but she only works once. After how many hours of cutting grass will John earn the same amount as his sister?
After 2.5 hours
2x+3y=28
-x-4y=-29
x=5 y=6
2x(2x2+3x-2)
4x3+6x2-4x
(a2 x a3)4
a20
2x2(-2x+3y)+y2(x2+3)
-4x3+6X2y+y2x2+3y2
A rectangle has a width of (3a+3) and a length of (7a-1). If the perimeter of the rectangle is 84 cm, what are the actually dimensions of the rectangle?
27cm x 15cm