You'll have to c<span>ompass tip on A and draw a small ark with pencil approximately in the middle above AB line, now compass tip to point B and cross the ark you made previously.
Do the same on the opposite side without making any change to the compass
Join the lines where crosses of arks on the both side meet and then ,it's done.</span>
Answers:
1. b = - 6
2. z = -7.5
3. c = 5
4. s = -38
5. w = 12
6. m = -(12/7)
7. k = 88
8. x = -10
9. t = -7.5
10. d = 0.3
11. "a" can be any value (Infinite solutions)
12. No solution for "n"
Solution:
1. -7(b+16)=7(b-4)
Dividing both sides of the equation by 7:
-7(b+16)/7=7(b-4)/7
-(b+16)=b-4
-b-16=b-4
-b-16+b+4=b-4+b+4
-12=2b
2b=-12
2b/2=-12/2
b=-6
Checking the solution:
-7(b+16)=7(b-4)
-7(-6+16)=7(-6-4)
-7(10)=7(-10)
-70=-70 Ok
2. 9-z=3z+39
9-z+z-39=3z+39+z-39
-30=4z
4z=-30
4z/4=-30/4
z=-7.5
Checking the solution:
9-z=3z+39
9-(-7.5)=3(-7.5)+39
9+7.5=-22.5+39
16.5=16.5 Ok.
3. 12c-5c=4c+15
7c=4c+15
7c-4c=4c+15-4c
3c=15
3c/3=15/3
c=5
Checking the solution:
12c-5c=4c+15
12(5)-5(5)=4(5)+15
60-25=20+15
35=35 Ok
4. 40-5s=-2(-1+3s)
40-5s=(-2)(-1)+(-2)(3s)
40-5s=2-6s
40-5s-40+6s=2-6s-40+6s
s=-38
Checking the solution:
40-5s=-2(-1+3s)
40-5(-38)=-2(-1+3(-38))
40+190=-2(-1-114)
230=-2(-115)
230=230 Ok
5. 2.8w+5.3=3.3w-0.7
2.8w+5.3-2.8w+0.7=3.3w-0.7-2.8w+0.7
6=0.5w
0.5w=6
0.5w/0.5=6/0.5
w=12
Checking the solution:
2.8w+5.3=3.3w-0.7
2.8(12)+5.3=3.3(12)-0.7
33.6+5.3=39.6-0.7
38.9=38.9 Ok
6. 4(m+9)=3(8-m)
(4)(m)+(4)(9)=(3)(8)+(3)(-m)
4m+36=24-3m
4m+36-36+3m=24-3m-36+3m
7m=-12
7m/7=-12/7
m=-12/7
Checking the solution:
4(m+9)=3(8-m)
4(-12/7+9)=3(8-(-12/7))
4(-12+7(9))/7=3(8+12/7)
4(-12+63)/7=3(7(8)+12)/7
4(51)/7=3(56+12)/7
204/7=3(68)/7
204/7=204/7 Ok
7. (1/8)k+32=(1/2)k-1
(1/8)k+32-32-(1/2)k=(1/2)k-1-32-(1/2)k
(1/8-1/2)k=-33
[(1-4(1))/8]k=-33
[(1-4)/8]k=-33
[(-3)/8]k=-33
(-3/8)k=-33
(-1)(-3/8)k=(-1)(-33)
(3/8)k=33
k=8(33)/3
k=264/3
k=88
Checking the solution:
(1/8)k+32=(1/2)k-1
(1/8)(88)+32=(1/2)(88)-1
(1)(88)/8+32=(1)(88)/2-1
88/8+32=88/2-1
11+32=44-1
43=43 Ok
8. (3/4)x-x=-(1/4)(2x+10)
Multiplying both sides of the equation by 4:
4(3/4)x-4x=-(4/4)(2x+10)
3x-4x=-1(2x+10)
-x=(-1)(2x)+(-1)(10)
-x=-2x-10
-x+2x=-2x-10+2x
x=-10
Checking the solution:
(3/4)x-x=-(1/4)(2x+10)
(3/4)(-10)-(-10)=-(1/4)(2(-10)+10)
-30/4+10=-(1/4)(-20+10)
-7.5+10=-(1/4)(-10)
2.5=10/4
2.5=2.5 Ok
9. 9(t+1)=5(t-4)-1
(9)(t)+(9)(1)=(5)(t)+(5)(-4)-1
9t+9=5t-20-1
9t+9=5t-21
9t+9-9-5t=5t-21-9-5t
4t=-30
4t/4=-30/4
t=-7.5
Checking the solution:
9(t+1)=5(t-4)-1
9(-7.5+1)=5(-7.5-4)-1
9(-6.5)=5(-11.5)-1
-58.5=-57.5-1
-58.5=-58.5 Ok
10. 3d+1.1=2.3-d
3d+1.1-1.1+d=2.3-d-1.1+d
4d=1.2
4d/4=1.2/4
d=0.3
Checking the solution:
3d+1.1=2.3-d
3(0.3)+1.1=2.3-0.3
0.9+1.1=2.0
2.0=2.0 Ok
11. -7(a+2)+15=1-7a
(-7)(a)+(-7)(2)+15=1-7a
-7a-14+15=1-7a
-7a+1=1-7a
-7a+1-1+7a=1-7a-1+7a
0=0
"a" can be any value (Infinite solutions)
Checking the solution: For example a=0
-7(a+2)+15=1-7a
-7(0+2)+15=1-7(0)
-7(2)+15=1-0
-14+15=1
1=1 Ok
12. 6(3n-1)=2(9n+4)
(6)(3n)+(6)(-1)=(2)(9n)+(2)(4)
18n-6=18n+8
18n-6+6-18n=18n+8+6-18n
0=14 It's not possible, because 0 is different to 14, then there is no solution for "n".
Answer:
the third term wasn't distributed properly the -2 has to multiply by +2 = -4
Step-by-step explanation:
-5x^2y - 3xy^2 - 2(4y+2) - 2.5x^2y
-5x^2y - 3xy^2 - 8y - 4 - 2.5x^2y
-7.5x^2y - 3xy^2 - 8y - 4
Answer:
16
Step-by-step explanation:
First, we plug in -3 in place of x...
f(x) = 2(-3)^2 + (-3) + 1
Then, we simplify each indidvidual expression...
f(x) = 18 - 3 + 1
Finally, we add/subtract all the values to get our answer...
f(x) = 16