8 klasa 25 maja
PRACA KONTROLNA
1. Trójkąt ABC równoramienny. Ramię AB = 17 cm, a
podstawa AC = 30 cm. Oblicz: a) obwód
trójkąta; b) wysokość BE; c) pole A ABC.
2. KLMN prostokąt, KL= 9,2 cm, PKLMN = 50 cm. Oblicz: a)
LM; b) SKLMN
b
3. S- pole trapezu, a i b- podstawy, h- wysokość. Oblicz pole
trapezu.
a = 17 cm, b= 31 cm, h=9 cm, S= ?
4. ABCD równoległobok, BF wysokość .Oblicz: a) wysokość
BF; b) pole równoległoboku, c) obwód równoległoboku.
12
5. a) Oblicz pole koła o promieniu 5 cm, odpowiedż zapisz z
literą . b)Oblicz pole koła o średnicy 3,4 cm. Weź =
3,14, odpowiedź zapisz z dokładnością do 0,1.
Obliczenia można wykonać przy pomocy kalkulatora. W
zadaniach 2, 3, 4, rysunki przerysowywać do zeszytu nie
trzeba.

1.true 2.false? ? i think. .

step-by-step explanation:

a.   we have two

lines:   y = 4-x   and  

y = 8-x^-1

given two simultaneous equations that are both to be

true, then the solution is the points where the lines cross. the intersection is

where the two equations are equal. therefore the solution that works for both

equations is when

4-x = 8-x^-1

this is where the two lines will cross and that is the

common point that satisfies both equations.

b.   4-x = 8-x^-1

  x           4-x       8-x^-1

-3           7        

8.33

-2           6         8.5

-1           5         9

  0           4        

-

  1           3        

7

  2           2        

7.5

  3           1         7.67

the table shows that none of the x values from -3 to 3 is

the solution because in no case does

4-x = 8-x^-1

to find the solution we need to rearrange the equation to

find for x:

4-x = 8-x^-1

multiply both sides with x:

4x-x^2 = 8x-1

x^2+4x-1=0

x= -4.236, 0.236

therefore there are two points that satisfies the

equation.

find y:  

x=-4.236

y = 4-x   = 4 – (-4.236)

= 8.236

y = 8-x^-1 =   .236)^-1

= 8.236

x=0.236

  y = 4-x   = 4 – (0.236) = 3.764

y = 8-x^-1 =   8-(0.236)^-1

= 3.764

thus the two lines cross at 2 points:

(-4.236, 8.236) & (0.236, 3.764)

c.   to solve

graphically the equation 4-x = 8-x^-1

we would graph both lines: y = 4-x   and   y

= 8-x^-1

the point on the graph where the lines cross is the

solution to the system of equations.

just graph the points on part b on a cartesian coordinate

system and extend the two lines.   the

solution is, as stated, the point where the two lines cross on the graph.

step-by-step explanation:

mark brainliest!

step-by-step explanation:   divide the numerator by the denominator to get the decimal

it would still be 193

if divide by 100 then 1.93

i am not sure