6×[(-3)+2) +4-(-4) ]​

S+D+K=155
K=S+10
D=S-20

S+(S-20)+(S+10)=155
S+S-20+S+10=155
3S-10=155
3S=165
S=165/3=55

If S=55,
K=55+10=65
D=55-20=35

Therefore, Sarah had worked for 55 hours, Kate had worked for 65 hours and Dave had worked for 35 hours.

Answered by Anonymous | 2024-06-10

Kate worked 10 hours more than Sarah. Dave worked 20 hours fewer than Sarah. A total of 155 hours worked. x --> Sarah y --> Dave z --> Kate
⎩ ⎨ ⎧ ​ x + y + z = 155 z = x + 10 y = x − 20 ​ ⎩ ⎨ ⎧ ​ x + x − 20 + x + 10 = 155 z = x + 10 y = x − 20 ​ ⎩ ⎨ ⎧ ​ 3 x = 165∣ : 3 z = x + 10 y = x − 20 ​ ⎩ ⎨ ⎧ ​ x = 55 z = 55 + 10 y = 55 − 20 ​ ⎩ ⎨ ⎧ ​ x = 55 z = 65 y = 35 ​
Now we see that Kate worked 65 hours, Dave worked 35 hours, and Sarah worked 55 hours.

Answered by MattD | 2024-06-10

Sarah volunteered 55 hours, Kate volunteered 65 hours, and Dave volunteered 35 hours. We found these values by setting up equations based on the relationships between their hours volunteered. After solving the equations, we calculated each sibling's contributions.
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Answered by Anonymous | 2024-10-09

Penyelesaian Langkah demi Langkah  Selesaikan operasi dalam kurung terdalam:  Operasi dalam kurung terdalam adalah \((-3)+2\). Hasilnya adalah \((-3)+2=-1\).  Ganti hasil ke dalam ekspresi: Ekspresi menjadi \(6\times [-1+4-(-4)]\).  Selesaikan operasi pengurangan negatif: Operasi \(-(-4)\) sama dengan \(+4\). Ekspresi menjadi \(6\times [-1+4+4]\).  Selesaikan operasi penjumlahan dalam kurung siku: Operasi dalam kurung siku adalah \(-1+4+4\). Hasilnya adalah \(-1+4+4=3+4=7\).  Selesaikan operasi perkalian terakhir: Ekspresi menjadi \(6\times 7\). Hasilnya adalah \(6\times 7=42\).

Answered by ravitapuji27 | 2025-08-23

Penjelasan dengan langkah-langkah:6 × [(-3) + 2 + 4 - (-4)]6 × [(-1) + 8]6 × 7 = 42Semoga membantu.

Answered by Opperheimer | 2025-08-23